P.W.

(Roads) Directorate Section : 2

Schedule : 2008-2009 General Specification

GENERAL SPECIFICATION
(INCLUDING MODE OF MEASUREMENT)

A: MATERIALS
All materials used in the works shall be of the best kind and to the approval of the Engineer-in-
Charge. All materials shall comply with the relevant Bureau of Indian Standard Specification.

A-1: Supply of Brick Materials

The minimum compressive strength of burnt clay bricks when tested flat shall not be less than 84
kg/cm2 for individual bricks and 105 kg/cm2 for average of 5 (five) specimens and the size may be
as mentioned below with a tolerance of ± 5 per cent.
(a) 1st class bricks conforming to IS: 1077 shall be manufactured with well pugged earth and
must be box moulded. The finished size of conventional bricks shall be 9 ¾˝ x 4 ¾˝ x 2 ¾˝.
These shall be of uniform size and colour, thoroughly and evenly burnt and should emit a
clear ringing sound, clearly when struck, be well shaped, square and true with even surface
and straight unbroken edges without cracks, rain spots, and flaws of any kind. These should
not absorb more than 1/6 of their weight of water when saturated.
(b) Picked Jhama Bricks shall be manufactured as at (a) above except that those shall be
slightly over-burnt. The shape, size etc. shall conform as far as practicable to those of 1st
class bricks.
(c) Jhama bats shall be obtained from uniformly vitrified and heavy picked jhama bricks and
the size should be ¼ to ¾ full bricks. The colour of bats shall be copper red to black and must
not be spongy. All lump jhama shall be broken to ½ brick size before it can be accepted as
bats.
(d) Jhama metal for road works, jhama chips for concrete works shall be obtained by breaking
good quality jhama bats, must not be spongy or with any coating of foreign material. The
metal or chips shall be of more or less cubical in shape and correspond to the specified range
of size.

A-2: Collection/Supply of hard Stone materials

Stone materials for road works or aggregate for cement concrete (plain or reinforced) shall be hard,
of uniform and fine texture, free from faults or planes of weakness and free from weathered faces.
These must also be free from loam, clay, or any surface coating, free from organic matter or other
impurities. The materials shall be stacked at road side lands or other lands (as directed by the
Engineer-in-Charge) in specified heights without causing inconvenience to traffic and in such a
way as to afford maximum facilities of work. Aggregates for Cement Concrete work should
conform to IS: 383. Physical requirements and grading of aggregates for pavement courses shall be
as specified for particular type of work. Stones when immersed in water for 24 hours shall not
absorb water by more than 5 percent of their dry weight when tested in accordance with IS: 1124.
(a) Hard stone boulders shall be supplied as per above specification regarding hardness, texture
etc. and shall be rough dressed with thickness (when laid as per natural bedding) closely
conforming to that specified.
(b) Road Metals shall be obtained by breaking large blocks conforming to above specification
regarding hardness etc. must be more or less cubical in shape and shall be well graded within
the range of size specified.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

(c) Stone chips shall be obtained by breaking large and hard blocks, must be cubical in shape
and graded within specified size range. These shall be washed clean as directed by the
Engineer-in-Charge.
(d) Shingles shall be hard, must have clean surface and on being broken the fractured surface
must indicate a uniform and fine texture free from laminations or planes of weakness. The
size shall be within specified limits.
(e) Gravels shall be as per shingles above, moreover these shall be washed clean before supply.
(f) Stone aggregate shall be designated by their standard sizes and shall conform to the
requirements set forth in Table A.2-1 The actual work of laying pavement course and
concrete works shall however be governed by the respective specifications of different works.
The size and quantities of aggregates to be supplied shall be so selected such that the grading
requirements for which the supply is intended are satisfied.
Table A.2-1: SIZE REQUIREMENTS FOR STONE AGGREGATES
Sl. No. Standard size of Designation of sieve through which the Designation of sieve on which
aggregate aggregate shall wholly pass the aggregate shall wholly be
retained

1 75 mm 105 mm 63 mm
2 63 mm 90 mm 53 mm
3 45 mm 53 mm 26.5 mm
4 26.5 mm 45 mm 22.4 mm
5 22.4 mm 26.5 mm 13.2 mm
6 13.2 mm 22.4 mm 11.2 mm
7 11.2 mm 13.2 mm 6.7 mm
8 6.7 mm 11.2 mm 2.8 mm
9 5.6 mm 9.5 mm 2.36 mm

A-3: Collection/Supply of Laterite Stone materials

Laterite shall be hard, compact, heavy and of dark colour. Light coloured Sandy laterite and also
those containing a good bit of ochreous clay shall not be used.
Laterite stone materials for road works shall be of good quality, free from dust, impurities and other
foreign material. The hardness shall be the maximum that is possible in this type of stone.
(a) Laterite boulders shall be as above regarding quality, of stone, shall be rough dressed and
must be supplied in thickness (when laid as per natural bedding) as specified.
(b) Laterite road metals shall be obtained by breaking good quality large laterite blocks must be
more or less cubical in shape and within the range of size specified.
(c) Moorum shall be of the best quality free of clay and must not be too brittlewhen dry nor too
sticky when wet.

A-4: Sand
Sand shall be clean, sharp and free from clay, loam, organic or other foreign matter and shall be
obtained from approved source. The contractor shall get the samples of sand to be used in different
kinds or work approved by the Engineer-in-Charge before using the same in work. Sand which in
the opinion of the Engineer-in-Charge or his representative is dirty must be washed to his
satisfaction at the cost and expenses of the contractor.

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
Sand may be classified as follows according to size :-
i) Coarse sand : 4.75 mm. to 2.00 mm. I.S. sieve
ii) Medium sand : 2.00 mm. to 425 micron I.S. sieve
iii) Fine sand : 425 micron to 75 micron I.S. sieve
Sand for all concrete works shall conform to provisions stipulated IS:383. The fineness modulus of
sand shall be greater than 2.0 and should be within 3.5
Medium sand may be used in cement mortar for masonry, plaster etc. and also for bituminous
works of road.
Silver sand may be used for low lying area filling work and non-structural work.

A-5: Cement
No cement excepting those supplied by the Department shall be used in work or brought to the site
by the contractor, unless the Contract has provision of supply of cement by the contractor. Cement
bags must be stored in a water-tight shed as approved by the Engineer-in-Charge. Any cement
damaged by water or otherwise defective shall be removed from site immediately. Grade of cement
to be used in the works shall have to be approved by the Engineer-in-Charge.

A-6: Steel
No steel excepting those supplied by the Department shall be used or brought to the site by the
contractor, unless the Contract has provision of supply of steel by the contractor. All steel shall be
of tested quality unless stipulated otherwise. These shall be free from oil, dirt and loose rust; any
scale or loose rust shall be removed before use, even though the same may have been supplied by
the department without any claim for extra charge for the purpose.

A-7: Timber
Timber shall be of first class quality, well seasoned and free from sap, loose and hard knots, shakes
or other defects. The timber used for structural purposes shall conform to IS: 883.

A-8: Paint
Paint used in the work shall be of the best quality or ready mixed paint. The make, brand and shade
of the paint must be to the prior approval of the Engineer-in-Charge. No paint other than the ready
mixed shall be used. Further, the paint shall be of make and brand as may be approved by the
Engineer-in-Charge, the paint must be brought to the site in original containers with the
manufacturer seal intact. Under no circumstances shall the paint be diluted with linseed oil or
otherwise.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B: GENERAL SPECIFICATION FOR EXECUTION

B-1 EARTHWORK FOR ROAD AND DRAINAGE EXCAVATION

B-1.1 Description
Roadway and Drainage excavation shall consists of excavation, removal and satisfactory disposal
of all materials necessary for the construction of roadway, site drains and water ways in accordance
with the requirements of these specification and the lines grades and cross sections shown in the
drawings or indicated by the Engineer-in-Charge. This work shall include the hauling and stacking
of or hauling to sites of embankment construction, of suitable cut materials are required, as also the
disposal of unsuitable cut materials in specified manner, and the trimming and finishing of the road
to specified dimensions or as directed by the Engineer-in-Charge.

B-1.1.1 Classification
All materials involved in excavation shall be classified by the Engineer in the following manner:

(a) Soil:-
This shall comprise top soil, turf, sand, silt, loam, clay, mud, peat, black cotton soil, soft
shale, loose moorum, a mixture of these and similar materials which yields to the ordinary
application of pick, spade and / or shovel etc. of ordinary digging implement. Removal of
gravel or any other nodular material having dimension in any direction not exceeding 75 mm.
occurring in such strata shall be deemed to be covered under this category.

(b) Ordinary Rock (not requiring blasting)

This shall include:-
(i) Rock type such as laterite, shale and conglomerate, varieties of limestone and sandstone
etc. which may be quarried or split with crow bars, also including any rock which in dry
state may be hard requiring blasting but which, when wet, becomes soft and manageable
by means other than blasting;
(ii) Macadam surfaces such as water bound and bitumen/tar bounds soling of roads, paths
etc. and hard core; compact moorum or stabilised soil requiring grafting tool or pick or
both and shovel, closely applied, gravel and cobble stone having maximum dimension in
any one direction between 75 and 300 mm.
(iii) Lime concrete, stone masonry and brick work below ground level, reinforced cement
concrete which may be broken up with crow bar or picks.
(iv) Boulder which do not require blasting having maximum dimension in any direction of
more than 300 mm. found lying loose on the surface or embedded in river bed, soil and
slope.

(c) Hard Rock (requiring blasting) shall include:-

(i) Any rock or cement concrete for the excavation of which the use of mechanical plant
and/or blasting is required;
(ii) Reinforced cement concrete (reinforcement cut through but not separated from the
concrete) below ground level and
(iii) Boulders requiring blasting

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
(d) Hard Rock (blasting prohibited)
Where blasting is prohibited and excavation to be carried out by chiselling wedging or any
other agreed method.

(e) Marshy soil

This shall include soils like soft clays and peats excavation below the original ground level of
marshy and swamps and soils excavated from areas requiring pumping or bailing out of
water.

B-1.2 Authority for classification

The classification for excavation shall be decided by the Engineer-in-Charge and his decision shall
be final and binding to the contractor. Merely the use of explosives in excavation will not be
considered as a reason for higher classification unless blasting is clearly necessary in the opinion of
the Engineer-in-Charge.

B-1.3 Construction operations :-

B-1.3.1 Setting out :

After the site has been cleared, the limits of excavation shall be set out true to lines, curves, slopes,
grades and sections, as shown on the drawings or as directed by the Engineer-in-Charge. The
contractor shall provide all labour, survey instruments and materials such as strings, pegs, nails,
bamboos, stones, lime, mortar, concrete etc. required in connection with the setting out of works
and establishment of bench marks. The Contractor shall be responsible for the maintenance of
bench marks and other marks and stakes as long as they required for the work in the opinion of the
Engineer-in-Charge.

B-1.3.2 Stripping and storing top soil

When so directed by the Engineer-in-Charge, the top soil existing over the sites of excavation shall
be stripped to specified depths and stored at designated locations for re-use in covering
embankment slopes, cut slopes, berms and other disturbed areas where re-vegetation is desired.
Prior to stripping the top soil, all trees, shrubs etc shall be removed along with their roots with
approval of the Engineer.

B-1.3.3 Excavation-General
All excavations shall be carried out in conformity with the directions laid herein under and in a
manner approved by the Engineer-in-Charge. The work shall be so planned that the suitable
materials available form excavation are satisfactorily utilised as decided upon before hand.
While planning or executing excavations, the contractor shall take all adequate precautions against
soil erosion, water pollution etc and take appropriate drainage measures to keep the site free of
water.
The excavation shall conform to the lines, grades, side slopes and levels shown on the drawings or
as directed by the Engineer-in-Charge. The Contractor shall not excavate outside the limits of
excavation. Subject to the permitted tolerances, any excess depth/width excavated below the
specified levels on the roadway shall be made good at the cost of the contractor with suitable
material of similar characteristics to that removed and compacted to the requirements of Clause B-
4.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

All debris and loose materials on the slopes of cutting shall be removed. No back filling shall be
allowed to obtain required slopes excepting that when boulders or soft materials are encountered in
cut slopes. These shall be excavated to approved depth on instructions of the Engineer-in-Charge
and the resulting cavities filled with suitable material and thoroughly compacted in an approved
manner.

B-1.3.4 Rock excavation

Rock, if encountered in roadway excavation, shall be removed up to the formation level or as
otherwise indicated in the drawings. Where, however, unstable shales or other unsuitable materials
are encountered at the formation level, these shall be excavated to the extent of 500 mm, below the
formation level or as otherwise specified. In all cases, the excavation operation shall be so carried
out that at no point on cut formation the rock protrudes above the specified levels. Rocks and large
boulders which are likely to cause differential settlements and also local drainage problems should
be removed to the extent of 500 mm below the formation level in full formation width including
drains and cut through side drains. Where excavation is done to levels lower that those specified,
the excess excavation shall be made as per Clauses B.1.3.3 and B.1.6 to the satisfaction of the
Engineer-in-Charge.
Slopes in rock cutting shall be finished to uniform lines corresponding to slope lines, shown on the
drawings or as directed by the Engineer-in-Charge. Not with standing the foregoing, all loose
pieces of rocks on excavated slope surface which move when pierced by a crow-bar shall be
removed. Where pre-splitting is prescribed to be done for the establishment of a specified slope in
rock excavation, the same shall be carried out as per Clause 303 of Specifications for Road &
Bridge Works of MoRT&H (4th Revision).

B-1.3.5 Excavation of road shoulders for widening of pavement

In works involving widening of existing pavements, unless otherwise specified, the shoulders shall
be removed to their full width and to levels shown on the drawings or as indicated by the Engineer-
in-Charge. While doing so, care shall be taken to see that no portion of the existing pavement
designated to be retained is loosened or disturbed. If the existing pavement gets disturbed or
loosened, it shall be dismantled and cut to a regular shape with sides vertical and the disturbed/
loosened portion removed completely and relayed as directed by the Engineer at the cost of the
Contractor.

B-1.3.6 Slides
If slides occur in cuttings during the process of construction, they shall be removed at the cost of
the contractor as ordered by the Engineer-in-Charge. If finished slopes slide into the roadway
subsequently, such slides shall be removed and paid for at the Contract rate for the class of
excavation involved provided the slides are not due to any negligence on the part of the contractor.
The classification of the debris material shall conform to its condition at the time of removal and
payment made accordingly regardless of its condition earlier.

B-1.3.7 Dewatering
If water is met within the excavations due to springs, seepage, rain or other causes, it shall be
removed by suitable diversion, pumping or bailing out, and the excavation kept dry whenever so
required or directed by the Engineer-in-Charge. Care shall be taken to discharge the drained water
into suitable outlets as not to cause damage to the works, crops or any other property. Due to any
negligence on the part of the Contractor, if any such damage be occurred, it shall be the sole
responsibility of the Contractor to repair / restore to the original condition at his own cost or
compensate for the damage.

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
B-1.3.7 Disposal of excavated materials
All the excavated materials shall be the property of the Government. Where the excavated material
is directed to be used in the construction of the embankment, it shall be directly deposited at the
required location complying with the requirements of Clause B-4. The operation shall be so
arranged that the capacity of cutting, haulage and compaction is nearly the same.
All hard materials, such as hard moorum, rubble, etc. not intended for use in the bank, shall be
stacked nearly for future use on Government land as directed by the Engineer-in-Charge within the
lead specified for the item. Unsuitable and surplus materials not intended for use in any part of the
road shall be disposed of as directed by the Engineer-in-Charge.

B-1.3.8 Back filling :

Back filling of masonry/concrete/hume pipe drain excavation shall be done with approved material
after concrete/masonry/hume pipe is fully set and carried out is such a way as not to cause undue
thrust on any part of the structure and/or not to cause differential settlement. All space between the
drain walls and the side of the excavation shall be refilled to the original surface making due
allowance for settlement, in layers generally not exceeding 150 mm compacted thickness to the
required density, using suitable compaction equipment such as mechanical tamper, rammer or plate
compactor as directed by the Engineer-in-Charge.

B-1.4 Plying of construction traffic

Construction traffic shall not use the cut formation and finished subgrade without the prior
permission of the Engineer-in-Charge. Any damage arising out of such use shall be made good by
the contractor at his own expense.

B-1.5 Preservation of property

The Contractor shall undertake all reasonable precautions for the protection and preservation of
any or all existing roadside trees, drains, or other sub-surface drains, pipes, conduits and any other
structures under or above ground, which may be affected by construction operation and which in
the opinion of the Engineer-in-Charge shall be continued in use without any change. Safeguards
taken by the contractor in this respect shall be got approved by him from the Engineer-in-Charge.
However, if any of these objects is damaged by reason of the contractor’s negligence, it shall be
replaced or restored to the original condition at his expense. If the Contractor fails to do so, within
the required time as directed by the Engineer or if, in the opinion of the Engineer, the actions
initiated by the Contractor to replace/ restore the damage objects are not satisfactory, the Engineer
shall arrange the replacements/ restoration directly through any other agency at the risk and cost of
the Contractor after issuing a prior notice to the effect.

B-1.6 Preparation of cut formation

The cut formation shall be prepared to receive the sub-base / base course as directed by the
Engineer-in-Charge.
Where the material is in a poor state of compaction (that is densities less than 95 per cent of the
maximum dry density determined according to IS: 2720 (Part VIII) is met with at the sub-grade
level, the same shall be loosened to a depth of 500 mm. and compacted in 250 mm. thick loose
layers in accordance with the requirements of Clause B-4. Any unsuitable material encountered at
the formation level shall be removed to a depth indicated by the Engineer-in-Charge and be
replaced with suitable material compacted in accordance with Clause B-4.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

In rocky formations, the surface irregularities shall be corrected and the levels brought up to the
specified elevation with sub-base or base material as directed by the Engineer-in-Charge, laid and
compacted in accordance with the respective specifications for these materials.

B-1.7 Finishing operations

Finishing operations shall include the work of properly shaping and dressing all excavated surfaces.
When completed, no point on the slopes shall vary from the designated slopes by more that 150
mm measured at right angles to the slope except where excavation is in rock (hard or soft) where no
point shall vary more than 300 mm. from the designated slope. In no case shall any portion of the
slope encroach on the roadway.
The finished cut formation shall satisfy the surface tolerances described in Clause 902 of the
Specifications of Roads & Bridges of MORTH (4th Revision)
Where directed, the top soil removed earlier and conserved shall be spread over the cut slopes,
where feasible, berms and other disturbed areas. Slopes may be roughened and moistened slightly,
prior to the application of top soil in order to provide satisfactory bond. The depth of top soil shall
be sufficient to sustain plant growth, usual thickness being from 75 mm to 100 mm.

B-1.8 Measurements for Payment

Excavation for roadway shall be measured by taking cross sections at suitable intervals in the
original position before the work starts and after its completion and computing the volumes in cubic
meter by the method of average end areas for each class of material encountered. Where it is not
feasible to compute volumes by this method because of erratic location of isolated deposits, the
volumes shall be computed by other accepted methods.
At the option of the Engineer, the Contractor shall leave depth indicators during excavations of
such shape and size and in such positions as directed so as to indicate the original ground level as
accurately as possible. The Contractor shall see that these remain intact till the final measurements
are taken.
For rock excavation, the overburden shall be removed first so that necessary cross-sections could be
taken for measurements. Where cross sectional measurements could not be taken due to irregular
configuration or where the rock is admixed with other classes of materials, the volumes shall be
computed on the basis of stacks of excavated rubble after making 35% deduction therefrom. When
volumes are calculated in this manner for excavated material other than rock, deduction made will
be to the extent of 16% of stacked volumes.
Works involved in the preparation of cut formation shall be measured in units indicated below
(i) Loosening and re-compacting the loosened material at sub- ……………….. cubic meter
grade
(ii) Loosening and removal of unsuitable material and replacing ……………….. cubic meter
with a suitable material and compacting to required density.
(iii) Preparing rocky sub-grade. ……………….. square meter
(iv) Stripping including storing and re-application of topsoil. ……………….. cubic meter
(v) Disposal of surplus material beyond initial 1000 m lead ……………….. cubic meter

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification

B-2 BLASTING OPERATION

B-2.1 General
Blasting shall be carried out in a manner that completes the excavation to lines indicated in
drawings, with the least disturbance to adjacent material. It shall be done only with the written
permission of the Engineer-in-Charge. All the statutory laws, regulations rules etc. pertaining to the
acquisition, transport, storages, handling and use of explosives shall be strictly followed.
The contractor may adopt any method or methods of blasting consistent with the safety and job
requirements, after approval from the Engineer-in-Charge. Prior to starting any phase of the
operation, the Contractor shall provide information describing pertinent blasting procedures,
dimensions and notes.
The magazine for the storage of explosives shall be built to the designs and specifications of the
Explosives Department concerned and located at the approved site. No unauthorised person shall be
kept admitted into the magazine which when not in use shall be kept securely locked. No matches
or inflammable material shall be allowed in the magazine. The magazine shall have an effective
lightening conductor. The following shall be hung in the lobby of the magazine:
(i) A copy of the relevant rules regarding safe storage both in English and in the
language which the workers concerned is familiar.
(ii) A statement of up-to date stock in the magazine.
(iii) A certificate showing the last date of testing of the lighting conductor.
(iv) A notice that smoking is strictly prohibited.
All explosives shall be stored in a secure manner in compliance with all laws and ordinances, and
all such storage places, shall be provided to the satisfaction of the Engineer-in-Charge and in
general not closer than 300 m from the road or from any building or camping area or place of
human occupancy.
In addition to these, the Contractor shall also observe the following instructions and any further
additional instructions which may be given by the Engineer-in-Charge and shall be responsible for
damage to property and any accident which may occur to work-men or the Public on account of any
operations connected with the storage, handling or use of explosives and blasting. The Engineer-in-
Charge shall frequently check the contractor’s compliance with these precautions.

B-2.2 Materials, Tools & Equipments

All the materials, tools and equipment used for blasting operations shall be of approved type. The
Engineer-in-Charge may specify the type of explosives to be allowed in special cases.
The fuse to be used in wet locations shall be sufficient water resistant as to be unaffected when
immersed in water for thirty minutes. The rate of burning of the fuse shall be uniform and definitely
known to permit such a length being cut as will permit sufficient time to the firer to reach safely
before explosion takes place.
Detonators shall be capable of giving effective blasting of the explosives. The blasting powder,
explosives, detonators, fuses, etc. shall be fresh and not damaged due to damp, moisture or any
other course. They shall be inspected before use and damaged articles shall be discarded totally and
removed immediately.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-2.3 Personnel
The blasting operation shall remain in the charge of competent and experienced supervisor and
workmen who are thoroughly acquainted with the details or handling explosives and blasting
operations.

B-2.4 Blasting operations

The blasting shall be carried out during fixed hours of the day preferably during the midday
luncheon hour or at the close of the work as ordered in writing by the Engineer-in-Charge. The
hours shall be made known to the people of the vicinity. All the charges shall be prepared by the
man-in-charge only.
The Contractor shall notify each public utility company having structures in proximity to the site of
the work of his intention to use explosives. Such notice shall be given sufficiently in advance to
enable the companies to take such steps as they may deem necessary to protect their property from
injury. In advance to any blasting work within 50 m of any railway track or structures, the
Contractor shall notify the concerned Railway Authority of the location, date, time and approximate
duration of such blasting operations.
Red danger flags shall be displayed prominently in all directions during the blasting operation.
People, except those who actually light the fuse, shall be prohibited from entering this area. The
flags shall be planted 200 meters from the blasting site in all directions and all persons including
workmen shall be excluded from flagged area at least 10 minutes before the firing, a warning
whistle being sounded for the purpose.The charge holes shall be drilled to required depths and in
suitable places. Blasting should be as light as possible consistent with thorough breakage of the
materials necessary for economic loading and hauling. Any method of blasting which leads to over
shooting shall be discontinued.
When blasting is done with powder, the fuse cut to the required length shall be inserted into the
hole and the powder dropped in. The powder shall be gently temped with copper rods with rounded
ends. The explosive powder shall then be covered with tamping material which shall be tamped
lightly but firmly.When blasting is done with dynamite and with other explosive, dynamite
cartridges shall be prepared by inserting the square cut end of a fuse into the detonator and finishing
it with nippers at the open-end, the detonator gently pushed into the primer leaving 1/3 rd of the
copper fuse exposed outside. The paper of the cartridge shall then be closed up and securely bound
with wire of twine. The primer shall be housed into the explosive. The borehole shall be of such
size that the cartridge can easily go down. The holes shall be cleared of all debris and explosive
inserted. The space of about 20 cm. above the charges shall then be gently filled with dry clay
pressed home and rest of the tamping formed of any convenient material gently packed with a
wooden rammer.
At a time, not more than ten such charges will be prepared and fired. The man in charge shall blow
a whistle in a recognized manner for cautioning the people. All the people shall then be required to
move to safe distances. The charges shall be lighted by the main in charge only. The man-in-charge
shall count the number of explosions. He shall satisfy himself that all the charges have been
exploded before allowing the workmen to go back to the work site.
After blasting operations, the Contractor shall compact the loose residual material below subgrade
and replace the material removed below subgrade with suitable material.

B-2.5 Misfire
In case of misfire, the following procedure shall be observed.

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
(i) Sufficient time shall be allowed to account for the delayed blast. The man in charge shall
inspect all the charges and determine the missed charge.
(ii) If it is the blasting powder charge shall the completely flooded with water. A new hole shall
be drilled at about 45 cm. from the old hole and fired. This should blast the old charge.
Should it not blast the old charge, the procedure shall be repeated till the old charge is
blasted.
(iii) In case of charges of gelignite, dynamite, etc., the man in charge shall gently remove the
tamping and the primer with the detonator. A fresh detonator and primer shall then be used
to blast charge. Alternatively the hole may be cleared of 30 cm. of tamping and the direction
then ascertained by pressing a stick in the hole. Another hole may then be drilled 15 cm.
away and parallel to it. This hole shall then be charges and fired when the misfired hole
should explode at the same time. The man in charge shall at once report to the contractor’s
office and Engineer-in-Charge all cases of misfire, the cause of the same and what steps
were taken in connection therewith.
(iv) If a misfire has been found to be due to defective detonator or dynamite, the whole quantity
in the box from which defective article was taken must be sent to the Authority directed by
the Engineer-in-Charge for inspection to ascertain whether all the remaining materials in the
box are also defective.

B-2.6 Account
A careful and day to day account of the explosives shall be maintained by the contractor in an
approved register and manner which shall be open to inspection by the Engineer-in-Charge at all
times.

B-3 EXCAVATION FOR STRUCTURE

B-3.1 Scope
Excavation for structures shall consist of removal of material for the construction of foundations for
bridges, culverts, retaining walls, headwalls, cut-off walls, pipe culverts and other similar
structures, in accordance with the requirements of these specifications and the lines and dimensions
shown on the drawing or as indicated by the Engineer-in-Charge. The work shall include the
construction of cofferdams and in where necessary their subsequent removal, all necessary
sheeting, shoring, bracing, draining and pumping, the removal of all logs, stumps, grubs, and other
deleterious matter and obstruction necessary for placing the foundations, trimming bottoms of
excavation; backfilling and clearing up the site and disposal of all surplus materials.

B-3.2 Classification of Excavation

All materials involved in excavation shall be classified in accordance with Clause B.1.1.1.

B-3.3 Construction operations

B.3.3.1 Setting out
After the site has been cleared, the limits of excavation shall be set out true to lines as per Clause B-
1.3.1.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B.3.3.2 Excavation
Excavation shall be taken to the width of the lowest step of the footing and the sites shall be left
plum where the nature of the soil allows it. Where the nature of the soil or the depth of the trench
does not permit vertical sides, the contractor shall put necessary shoring, strutting and planking or
cut slopes to a safer angle or both with due regard to the safety or personnel and works and to the
satisfaction of the Engineer-in-Charge.
The depth to which the excavation is to be carried out shall be as shown on the drawings, unless the
type of material encountered in such as to require changes, in which case the depth shall be as
ordered by the Engineer-in-Charge. Propping shall be undertaken when any footing or stressed
zone from an adjoining structure is within a line of 1 vertical to 2 horizontal from the bottom of the
excavation. Where blasting is to be resorted to, the same shall be carried out to Clause B-2 and all
precautions therein observed.

B.3.3.3 Dewatering and protection

Normally open foundation shall be laid dry. Where water is met within excavation due to stream
flow, seepage, spring, rain or other reasons, the contractor shall take adequate measures such as
bailing, pumping, constructing diversion channels, drainage channels, bunds, depression of water
level by well point system, cofferdams and other necessary works to keep the foundation trenches
dry when so required and to protect the green concrete/masonry against damage by erosion or
sudden rising of water level. The methods to be adopted in this regard and other details thereof
shall be left to the choice of the contractor but subject to approval of the Engineer-in-Charge.
Approval of the Engineer-in-Charge shall, however, not relieve the contractor of the responsibility
for the adequacy of dewatering and protection arrangements for the quality and safety of the works.
Where cofferdams are required, these shall be carried to adequate depths and heights be safely
designed and constructed and be made watertight as is necessary for facilitating construction to be
carried out inside them. Interior dimensions of the cofferdams shall be such as to give sufficient
clearance for the construction and inspection and to permit installation of pumping machinery etc.
inside the enclosed area.
If it is determined beforehand that the foundations can not be laid dry or the situation is found that
the percolation is too heavy for keeping the foundation dry, the foundation concrete shall be laid
under water by tremie pipe only. In case of flowing water or artesian springs, the flow shall be
stopped or reduced as far as possible at the time of placing the concrete.
Pumping from the interior of any foundation enclosure shall be done in such a manner as to
preclude the possibility of the movement of water through any fresh concrete. No pumping shall be
permitted during the placing of concrete for any period of at least 24 hours thereafter, unless it is
done from a suitable sump separated from the concrete work by a water-tight wall or other similar
means.
At the discretion of the contractor, cement grouting or other approved methods may be used to
prevent or reduce seepage and to protect the excavation area.
The contractor shall take all precautions in diverting channels and in discharging the drained water
as not to cause damage to the works, crops, or any other property.

B.3.3.4 Preparation of foundation :

The bottom of the foundation shall be levelled both longitudinally and transversely or stepped as
directed by the Engineer-in-Charge. Before footing is laid, the surface shall be slightly watered and
rammed. In the event of excavation, having been made deeper than that shown on the drawings or
as otherwise ordered by the Engineer-in-Charge, the extra depth shall be made up with concrete or

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P.W.(Roads) Directorate Section : 2
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masonry of the foundation grade at the cost of contractor. Ordinary filling, shall not be used for the
purpose to bring the foundation to level.
When rock and other strata is encountered, it shall be freed of all soft and loose material, cleaned
and cut to a firm surface either level and stepped as directed by the Engineer-in-Charge. All seams
shall be cleaned out filled with cement mortar or grout to the satisfaction of the Engineer-in-
Charge. In the case of excavation of rock, annular space around footing shall be filled with lean
concrete (1:3:6 nominal mix) up to the top level of rock.
When foundation piles are used, the excavation of each pit shall be substantially completed before
beginning pile driving operations therein. After pile driving operations in a given pit are completed,
all loose and displaced materials therein shall be removed to the elevation of the bottom of the
footings.

B.3.3.5 Slips and Slip-outs :

If there are any slips or slip-outs in the excavation, there shall be removed by the contractor at his
own cost.

B.3.3.6 Public safety :

Near town, villages and all frequented places, trenches and foundation pits shall be securely fenced,
provided with proper caution signs and marked with red lights to avoid accidents. The contractor
shall take adequate protective measures to see that the excavation operations do not affect or
damage adjoining structures. For safety precautions, guidance may be taken from IS: 3764.

B.3.3.7 Back filling :

Back filling shall be done with approved material after concrete or masonry is fully set and carried
out in such a way as not to cause under thrust on any part of the structure. All space between
foundation masonry or concrete and the sides of excavation shall be refilled to the original surface
in layers not exceeding 150 mm compacted thickness. The compaction shall be done with the help
of suitable equipment such as mechanical tamper, rammer, plate vibrator, etc after necessary
watering, so as to achieve a density not less than the field density before excavation.

B.3.3.8 Disposal of surplus excavated materials :

Clause B-1.3.8 shall apply.

B-3.4 Measurements for Payments

Excavation for structures shall be measured in cubic meters for each class of materials encountered,
limited to the dimensions shown on the drawings or as directed by the Engineer. Excavation over
increased width, cutting of slopes, shoring, shuttering and planking shall be deemed as convenience
for the Contractor in executing the work and shall not be measured and paid for separately.
Preparation of rock foundation shall be measured in square meters.
Foundation sealing, dewatering including pumping shall be deemed to be incidental to the work
unless separate provision is made for in the contract. In the latter case, payment shall be on lump-
sum basis as provided in the Bill of Quantities.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-4 EMBANKMENT CONSTRUCTION

B-4.1 Description
These specifications shall apply to the construction of embankments including sub-grades, earthen
shoulders and miscellaneous back fills with approved material obtained either from excavation for
road construction, borrow pits or other sources. All embankments shall be constructed in
accordance with the requirements of these specifications and in conformity with the lines, grades
and cross-sections shown on the drawings or as directed by the Engineer-in-Charge.

B-4.2 Materials

B-4.2.1 Physical requirements and General requirements

The materials used in embankments, sub-grades, earthen shoulder & miscellaneous backfills shall
be soil, moorum, gravel, a mixture of these or any other materials approved by the Engineer-in-
Charge. Such materials shall be free of logs, stumps, roots, rubbish or any other ingredient likely to
deteriorate or affect the stability of the embankment /subgrade.
The following types of material shall be considered unsuitable for embankment:
i) Materials from swamps, marshes and bogs;
ii) Peat, log, stump and perishable material; any soil that classifies as OL, OI, OH or PT in
accordance with IS: 1498.
iii) Materials which are susceptible to spontaneous combustion.
iv) Materials which are in a frozen condition.
v) Clay having liquid limit exceeding 70 and plasticity index exceeding 45.
vi) Materials with salts, resulting in leaching in the embankment.
Expansive clay exhibiting marked swell and shrinkage properties (“free swelling index” exceeding
50% when tested as per IS: 2720-Part 40) shall not be used as a fill material. Where expansive clay
with acceptable “free swelling index” value is used as a fill material, subgrade and top 500 mm
portion of the embankment just below the subgrade shall be non-expansive in nature.
The size of the coarse material in the mixture of earth shall ordinarily not exceed 75 mm when
being used in the embankment and 50 mm when placed in the subgrade. However, the Engineer-in-
Charge may at his discretion permit the use of material coarser than this also if he is satisfied that
the same will not present any difficulty as regards the placement of fill material and its compaction
to the requirements of these specifications. The maximum particle size shall not be more than two-
thirds of the compacted layer thickness.
Ordinarily, only the materials, satisfying the density requirement given in Table B 4.2-1 shall be
employed for construction of embankment/subgrade.
Table B 4.2-1: Density requirements of Embankment and Subgrade materials
Maximum laboratory dry density when
Sl.
Type tested as per
No.
IS:2720 (Part VIII)
Embankment up to 3 meter height not subjected to extensive
1. Not less than 15.2 KN/cum.
flooding.
Embankment exceeding 3 meter height or embankments of any
2. Not less than 16.0 KN/cum.
height subject to long periods or inundation.
3. Sub-grade and earthen shoulders/ verges/ backfill. Not less than 17.5 KN/cum.
Notes:
1) This Table is not applicable for lightweight fill material e.g., cinder, fly ash, etc.

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P.W.(Roads) Directorate Section : 2
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2) The Engineer may relax these requirements at his discretion taking into account the availability of materials for
construction and other relevant factors.
3) The material to be used in subgrade should also satisfy design CBR at the dry unit weight applicable as per Table
B-4.2-1

B-4.2.2 Source of supply

The materials for embankment shall be obtained from approved sources with preference given to
materials becoming available form nearby roadway excavation or any other excavation under the
same Contract.
The work shall be so planned and executed that the best available materials are saved for the
embankment/ subgrade portion just below the subgrade.
Where the materials are to be obtained from the approved borrow pits, the locations, size and shape
of these pits shall be as indicated by the Engineer-in-Charge and the same shall not be opened
without his written permission.
Borrow pits along the road shall be discouraged. If permitted by the Engineer-in-Charge, these shall
not be dug continuously. Ridges, having width not less than 8 meters, should be left at intervals not
exceeding 300 meters. Small drains shall be cut through the ridges to facilitate drainages. The depth
of the pits shall be so regulated that their bottom does not cut an imaginary line having a slope of 1
in 4 projected from the edge of the final section of the bank the maximum depth in any case being
limited to 1.5 meters. Also, no pit shall be dug within the offset width from the toe of the
embankment required as per the consideration of stability with a minimum width of 10 meters.
The Contractor shall obtain representative samples from each of the identified borrow areas and
have these tested at the site laboratory following a testing programme approved by the Engineer. It
shall be ensured that the subgrade material when compacted to the density requirements as in Table
B 4.2-2 shall yield the design CBR value of the subgrade.
The contractor shall at least 7 working days before the commencement of compaction submit the
following to the Engineer-in-Charge for approval:
(a) The values of maximum dry density and optimum moisture content, obtained in accordance with IS: 2720
(Part VII) or (Part VIII), as the case may be, appropriate for each of the fill materials intends to use.
(b) A graph of density plotted against moisture content from which each of the values in (i) above of maximum
dry density and optimum moisture content were determined.
(c) The Dry density- Moisture content- CBR relationships for light, intermediate and heavy compaction efforts
(light - corresponding to IS: 2720 (Part VII), heavy - corresponding to IS: 2720 (Part VIII) and intermediate -
in-between the two for each of the fill materials he intends to use in the subgrade.)
Table B 4.2-2: COMPACTION REQUIREMENT FOR EMBANKMENT & SUBGRADE
Relative compaction as percentage of
Type of work/ material maximum laboratory dry density, as per
IS:2720 (Pt VIII)

Sub-grade and earthen shoulders. Not less than 97%

Embankment. Not less than 95%

Expansive Clays
a) Sub-grade and 500 mm portion just below the subgrade. Not allowed.
b) Remaining portion of embankment. Not less than 90%

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-4.3 Construction operation

B-4.3.1 Setting out

After the site has been cleared the work shall be set out true to lines, curve, slopes, grades and
sections as shown on the drawings or as directed by the Engineer-in-Charge. The contractor shall
provide all labour, survey instruments and materials such as strings, pegs, nails, bamboos, stones,
lime, mortar, concrete, etc. required in connection with the setting out of the works and the
establishment of bench marks. The contractor shall be responsible for the maintenance of bench
marks and other marks and stakes as long as they are required for the work in the opinion of the
Engineer-in-Charge. The limits of embankment shall be marked by fixing better pegs on both sides
at regular intervals as guides before commencing the earth work. To ensure their safety, it is
desirable to fix the pegs about 0.5 meter back from the actual limits of the fill and paint them in a
distinctive colour.

B-4.3.2 Dewatering
If the foundation of the embankment is in an area with stagnant water, and in the opinion of the
Engineer-in-Charge it is feasible to remove it, the same shall be removed by bailing out or
pumping, as directed by the Engineer-in-Charge and the area of the embankment foundation shall
be kept dry. Care shall be taken to discharge the drained water so as not to cause damage to the
works, crops or any other property. Due to the negligence on the part of the Contractor, if any such
damage is caused, it shall be the sole responsibility of the Contractor to repair/ restore it to original
condition or compensate the damage at his own cost.

B-4.3.3 Stripping and storing top-soil

In localities where most of the available embankment materials are not conductive to plant growth,
or when so directed by the Engineer-in-Charge, the top soil existing over the embankment
foundation shall be stripped to specified depths not exceeding 150 mm and stored in stock piles of
height not exceeding 2 m for covering embankment slopes, cut slopes and other disturbed area
where re-vegetation is desired. Topsoil shall not be unnecessarily trafficked either before the
stripping or when in a stockpile. Stockpiles shall not be surcharged or otherwise loaded and
multiple handling shall be kept to a minimum.

B-4.3.4 Compacting ground supporting embankment/ subgrade:

Where necessary the original ground shall be levelled to facilitate placement of first layer of
embankment, scarified, mixed with water and then compacted by rolling so as to achieve the
minimum dry density as shown in the Table above. Where the height of the proposed embankment
is less than 0.5 meter and the original ground does not already have a relative compaction of at least
97 percent, the same be loosened to a depth of 0.5 meter below the subgrade level, watered and
compacted in layers not exceeding 250 mm. In loose thickness to the maximum dry density of the
materials determined in accordance with IS: 2720 (Part VIII). However, before relaying and
compacting the loosened material the surface below this level shall be suitably consolidated as
directed by the Engineer-in-Charge in accordance with Clauses B-4.3.4 and B-4.3.5 to not less than
97% of dry density as given in the Table above.
Where so directed by the Engineer-in-Charge, any unsuitable materials occurring in embankment
foundation shall be removed and replaced by approved materials laid in layers to the required
degree of compaction.
Embankment or sub-grade work shall not proceed until the foundation for embankment / sub-grade
have been inspected by the Engineer-in-Charge for satisfactory condition and approved.

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P.W.(Roads) Directorate Section : 2
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B-4.3.5 Spreading materials in layers and bringing to appropriate Moisture Content
The embankment and subgrade materials shall be spread uniformly in layers over the entire width
of the embankment, each layer not exceeding 200 mm. in compacted thickness. Successive layers
of embankment shall not be placed until the layer under construction has been thoroughly
compacted to the requirements set down here under. Each compacted layer shall be finished parallel
to the final cross section of the embankment
Moisture content of the material shall be checked at the site of placement prior to commencement
of compaction; if found to be out of agreed limits, the same shall be made good either at the source
or after, spreading the soil in loose thickness for compaction. In the later case, water shall be
sprinkled from a hose line and/or a truck mounted water tank capable of applying water uniformly
and at controlled quantities but without any flooding.
If the material delivered to the roadbed is too wet, it shall be dried, by aeration and exposure to the
sun, till the moisture content is acceptable for compaction. Should circumstances arise, where
owing to wet weather, the moisture content cannot be reduced to the required amount by the above
procedure, work on compaction shall be suspended.
Moisture content of each layer of soil shall be checked in accordance with IS: 2720 (Part II) and
otherwise mentioned, shall be so adjusted, making due allowances for evaporation losses, that at the
time of compaction it is in the range of 1 percent above to 2 percent below the optimum moisture
content determined in accordance with IS: 2720 (Part VII) or IS: 2720 (Part VIII) as the case may
be.
Expansive clays shall, however, be compacted moisture content corresponding to the specified dry
density, but on the wet side of the optimum moisture content obtained from the laboratory
compaction curve.
After adding the required amount of water, the soil shall be processed by means of harrows,
graders, rotary mixers or as otherwise approved until the layer in uniformly wet.
Clods or hard lumps of earth shall be broken to have maximum size of 75 mm. when being placed
in the embankments and a maximum size of 50 mm. when being placed in the sub-grade
For other details Clause 305.3.5.3. of MORTH’s Specifications for Road & Bridge Works (4th
Revision) may be consulted.

B-4.3.6 Compaction
Only the compaction equipment approved by the Engineer-in-Charge shall be employed to compact
the different materials types encountered during construction. If directed by the Engineer-in-
Charge, the contractor shall demonstrate the efficiency of the plant be intends to use by carrying out
compaction trials.
Each layer of the materials shall be thoroughly compacted to the densities specified in Table B 4.3-
1.
Table B 4.3-1: COMPACTION REQUIREMENT FOR EMBANKMENT & SUBGRADE
Field dry density as a percentage of maximum
Sl. No. Type of work / material
laboratory dry density as per IS:2720 (Part VIII)
1. Sub-grade and earthen shoulders Not less than 97%

2. Other portion of embankment Not less than 95%

3. Highly expansive clays in embankment only Not less than 90%

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Section : 2 P.W. (Roads) Directorate
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Subsequent layers shall be placed only after the finished layer has been tested for the following and
accepted by the Engineer-in-Charge. A record for the same shall be maintained.

B-4.3.7 Tests on Earthwork for embankment sand sub-grade construction with borrow
material.
a) Sand Content : [IS:2720 (Part IV)] One to two tests per 8000m3 of soil.
b) Plasticity Test : [IS:2720 (Part V)] Each type to be tested, 1-2 tests per 8000m3 of
soil.
c) Density Test : [IS:2720 (Part VIII)] Each soil type to be tested, 1-2 tests per 8000m3
of soil.
d) Deleterious Content Test : [IS: 2720 (Part XXVII)] As and when required by the
Engineer-in-Charge.
e) Moisture Content Test : [IS: 2720 (Part II)] One test for every 250m3 of soil.
f) C.B.R. Test of materials to be incorporated in the sub-grade on soaked/un-soaked
sample : [IS: 2720 (Part XVI)] One test for every 3000m3 at least or closer as and
when required by the Engineer-in-Charge.
When density measurements reveal any soft areas in the embankment/ subgrade/ earthen shoulders
further compaction shall be carried out as directed by the Engineer-in-Charge. If in spite of that, the
specified compaction is not achieved, the material in the soft areas shall be removed and replaced
by approved material compacted to the density requirements and satisfaction of the Engineer-in-
Charge.

B-4.3.8 Compaction Control :

Control shall be exercised by taking at least one measurement of density for each 1000 sq. meters
of compacted area or closer as required to yield the minimum number of test results for evaluating a
day’s work on statistical basis. The determination of density shall be in accordance with IS: 2720
(Part XXVIII). Test locations shall be chosen only through random sampling techniques. Control
shall not be based on the result of any one test but on the mean value of a set of 5-10 density
determinations. The number of tests in one set of measurement shall be 5 as long as it is felt that
sufficient control over borrow materials and the method of compaction is being exercised. If
considerable variations are observed between individual density results the minimum number of
tests in one set of measurement shall be increased to 10. The acceptance of work shall be subject to
the condition that the mean dry density equals or exceeds the specified density and the standard
deviation for any set of results in below 0.08 gm/c.c.
However, for earthwork in shoulder and in top 500 mm. portion of the embankment below the sub-
grade, at least one density measurement shall be taken for every 500 sq. meters of the compacted
area provided further that the number of tests in each set of measurement shall be at least 10.

B-4.3.9 Drainage :
The surface of the embankment / sub-grade at all times during construction shall be maintained at
such a cross fall (not flatter than that required for effective drainage of an earthen surface) as will
shed water and prevent ponding.

B-4.3.10 Repairing of damages caused by rain/ spillage of water:

The soil in the affected portion shall be removed in such areas as directed by the Engineer-in-
Charge before the next layer is laid and refilled in layers and compacted using appropriate

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P.W.(Roads) Directorate Section : 2
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mechanical means such as small vibratory roller, plate compactor or power rammer to achieve the
required density in accordance with Clause B-4.3.5. if the cut is not sufficiently wide for use of
required mechanical means for compaction, the same shall be widened suitably to permit their use
for proper compaction.
Tests shall be carried out as directed by the Engineer-in-Charge to ascertain the density
requirements of the repaired area. The work of repairing the damages including widening of the cut,
if any, shall be carried out by the Contractor at his own cost, including the arranging of
machinery/equipment for the purpose.

B-4.3.11 Finishing Operations

Finishing operations shall include the work of shaping and dressing the shoulders/verge/road bed
and side slopes to conform to the alignment, levels, cross section and dimensions shown in the
drawings or as directed by the Engineer-in-Charge subject to surface tolerances as stated under
“Control of Alignment and surface Regularity”. Both the upper and lower ends of the side slopes
shall be rounded off to improve appearance and to merge the embankment with the adjacent terrain.
The top soil, removed and conserved earlier shall be spread over the fill slopes as per the direction
to facilitate the growth of vegetation. Slopes shall be roughened and moistened slightly just prior to
the application of the top soil, in order to provide satisfactory bond. The depth of the top soil shall
be sufficient to sustain plant growth, the usual thickness being from 75 to 150 mm.
Where directed, the slopes shall be turfed with sods in accordance with Clause B 4.3.12. If seeding
and mulching of slopes is prescribed, this shall be done to the requirement of Clause 308 of
MORTH’s Specifications for Road & Bridge Works (4th Revision).
When earth work operations have been substantially completed, the road area shall be cleared of all
debris and ugly scars in the construction area responsible for objectionable appearance eliminated.

B-4.3.12 Turfing with Sods

This work shall consist of furnishing and laying of the live sod of perennial turf forming grass on
embankment slopes, verges or other locations shown on the drawings or as directed by the
Engineer. The work shall be taken up as soon as possible following construction of embankment
provided the season is favourable for establishment of the sod.
The sod shall consist of dense, well rooted growth of permanent and desirable grasses and free from
weeds or other undesirable matter. At the time the sod is cut, the grass on the sod shall have a
length of approximately 50 mm. The thickness of the sod shall be as uniform as possible, with
some 50-80 mm or so of soil covering the grass roots so that the root system of the grasses is
retained in the sod strip. The sods shall be cut of sizes of about 250 mm. x 300 mm. for easy
handling and transportation. During wet weather, the sod shall be allowed to dry sufficiently and
during dry weather shall be watered before lifting to ensure its vitality and prevent the dropping of
the soil in handling.
The area to be sodded shall have been previously constructed to the required slope and cross
section. Soil on the area shall be loosened for receiving the sod. The prepared bed shall be
moistened to the loosened depth, if not sufficiently moist, and the sod shall be placed there on
within 24 hours after the same had been cut. Each sod strip shall be laid edge to edge with abutting
ends are staggered. Each strip after it is placed in proper position shall be lightly tamped with
suitable wooden tampers to press it into underlying soil. After the sods have been laid in position,
the surface shall be cleaned of loose sod. The area shall be thoroughly moistened by sprinkling with
water. The sods shall be watered for a period of at least four weeks after laying.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-4.4 Construction of Embankment and Sub-grade under Special Conditions

B-4.4.1 Earthwork for widening existing road embankment
When an existing embankment and/ or subgrade is to be widened and its slopes are steeper than 1
vertical on 4 horizontal, continuous horizontal benches, each at least 0.3 meter wide, shall be cut
into the old slope for ensuring adequate bond with the fresh-embankment / sub-grade, with the
material to be added. The material obtained from cutting of benches could be utilized in the
widening of the embankment. However, when the existing slope against which the fresh material is
to be placed is flatter than 1 vertical on 4 horizontal, the slope surface may only be ploughed or
scarified instead of resorting to benching.
Where the width of the widened portion in insufficient to permit the use of conventional rollers,
compaction shall be carried out with the help of small vibratory rollers/ plate compactors/ power
rammers or any other approved equipment. End dumping of materials from trucks for widening
operations shall be avoided except in difficult circumstances when the extra width is too narrow to
permit the movement of any other type of hauling equipment.
B-4.4.2 Earthwork over existing road surface
Where the embankment is to be placed over an existing road surface the work shall be carried out
as indicated below:-
(i) If the existing road surface is of granular or bituminous type and lies within 1 m. of the new
sub-grade level, the same shall be scarified to a depth of 50 mm or more if specified so as to
provide ample bond between the old and new materials, ensuring that at least 500 mm.
portion below the top of new sub-grade level is compacted to the desired density.
(ii) If the existing road is of cement concrete type and lies within 1 m. of the new sub-grade level,
the same shall be removed completely.
(iii) If the level difference between the existing road surface and new formation level is more than
1 m. the existing surface shall be permitted to stay in place without any modification.
B-4.4.3 Embankment and Sub-grade around structures
To avoid interference with the construction of abutments, wing-walls or return walls of
culvert/bridge structures, the Contractor shall, at points to be determined by the Engineer-in-Charge
suspend work on embankments forming approaches to such structures, until such time as the
construction of latter is sufficiently advanced to permit the completion of approaches without the
risk of interference or damage to the structure.
Unless directed otherwise, the filling around culverts, bridges and other structures up to a distance
of twice the height of the embankment from the back of the abutment shall be carried out
independent of the work on the main embankment. The fill material shall not be placed against any
abutment or wing wall, unless permission has been given by the Engineer-in-Charge but in any case
not until the concrete or masonry has been in position for 14 days. The embankment and sub-grade
shall be brought up simultaneously in equal layers on each side of the structure to avoid
displacement and unequal pressure. The sequence of work in this regard shall be got approved from
the Engineer-in-Charge.
The material used for back filling shall not be an organic soil or highly plastic clay having
‘Plasticity Index’ and ‘Liquid Limit’ more than 20 and 40 respectively when tested according to IS:
2720 (Part V). The fill material shall be deposited in horizontal layers in loose thickness and
compacted thoroughly to the requirement of Table 4.3-1.
Where the provision of any filter medium is specified behind the abutment, the same shall be laid in
layers simultaneously with the laying of fill material. The material used for filter shall conform to

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
the requirements for filter medium spelt out as per Clause 305.4.4 of MORTH’s Specifications for
Road & Bridge Works (4th Revision).
Unless it requires to be designed on inverted filter criteria for filtration and permeability to the
approval of the Engineer-in-Charge, it shall meet the following grade requirements as per Table B
4.4-1.
Where it may be impracticable to use conventional rollers, the compaction shall be carried out by
appropriate mechanical means such as small vibratory rollers, plate compactors or power rammer
as approved by the Engineer-in-Charge. Care shall be taken to see that compaction plant does not
hit or come too close to any structural members so as to cause any damage to them or excessive
pressure against the substructure.
Table B 4.4-1: GRADING REQUIREMENT OF FILTER MATERIAL
Percent (%) by Weight Passing the Sieve
Sieve Designation
Class I Class II Class III

53 mm. - - 100
45 mm. - - 97-100
26.5 mm. - 100 -
22.4 mm. - 95-100 58-100
11.2 mm. 100 48-100 20-60
5.6 mm. 92-100 28-54 4-32
2.8 mm. 83-100 20-35 0-10
1.4 mm. 59-96 - 0-5
710 micron. 35-80 6-18 -
355 micron 14-40 2-9 -
180 micron 3-15 - -
90 µm 0-5 0-4 0-3
Type of Soil in the trench Grading to be used
(i) Fine grained Type : Class I
(ii) Coarse Silt to Medium Sand : Class II
(iii) Gravelly Sand : Class III

B-4.4.4 Embankment construction under water

Where filling or back filling is to be placed under water, only acceptable granular material or rock
shall be used unless otherwise approved by the Engineer. Acceptable granular material shall consist
of graded, hard durable particles with maximum particle size not exceeding 75 mm. The material
shall be non-plastic having uniformity coefficient of not less than 10. The material placed in open
water shall be deposited by end tipping without compaction.

B-4.4.5 Earth work for high embankment

In case of high embankment the agency should normally use the material from the specified borrow
area. In case he desires to use different materials for his own convenience, he shall have to carry
out necessary soil investigations and redesign the high embankment at his own cost. The Contractor
shall then furnish the soil test data and design of high embankment for approval of the Engineer-in-
Charge, who reserves the right to accept or reject it. If necessary, stage construction of fills and any
controlled rates of filling shall be carried out including installation of instruments for its monitoring
and control as per direction of Engineer. Where required, the contractor shall surcharge the
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Section : 2 P.W. (Roads) Directorate
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embankment or other areas of fill with approved material for the periods as specified by the
Engineer. Where surcharge material is to be kept for the specified period to monitor the settlement
of the embankment, the surcharged material shall remain in place for the required settlement period
before further work. The duration of the settlement period shall be specified by the Engineer.

B-4.4.6 Earthwork for embankment & subgrade to be placed against sloping ground
Where an embankment/sub-grade is to be placed against sloping ground, the latter shall be
appropriately benched or ploughed/scarified as required before placing the embankment/subgrade
material. Extra earthwork involved in benching or due to ploughing/scarifying etc shall be
considered incidental to the work.
For wet conditions, benches with slightly inward fall and subsoil drains at the lowest point shall be
provided as per the drawings, before the fill is placed against the sloping ground.
Where the Contract requires construction of transverse subsurface drain at the cut-fill interface,
work on the same shall be carried out to Clause 309 of MORTH’s Specifications for Road &
Bridge Works (4th Revision), in proper sequence with the embankment and subgrade work as
approved by the Engineer-in-Charge.

B-4.4.7 Settlement period

Where settlement period is specified in the Contract, the embankment shall remain in place for the
required settlement period before excavating for abutment, wing wall, retaining structure, footings,
etc. or driving foundations piles. The duration of the required settlement period at each location
shall be provided for in the Contract or as directed by the Engineer-in-Charge.

B-4.4.8 Plying of Traffic

Construction and vehicular traffic shall not use the prepared surface of the embankment and/or sub-
grade without the prior permission of the Engineer-in-Charge. Any damage arising out of such use
shall however, be made good by the contractor at his own cost as directed by the Engineer-in-
Charge.

B-4.4.9 Sub-grade Strength

It shall be ensured prior to actual execution that the borrow area material to be used in the subgrade
satisfies the requirements of design CBR.
Subgrade shall be compacted and finished to the design strength consistent with other physical
requirements. The actual laboratory CBR values of constructed subgrade shall be determined on
undisturbed samples cut out from the compacted subgrade in CBR mould fitted with cutting shoe or
on remoulded samples, compacted to the field density at the field moisture content.

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B-5 STABILISED SOIL SUB-BASE

B-5.1 Description
This work shall consist of laying and compacting a sub-base course of mechanically stabilised soil
or soil stabilised with lime or cement on prepared sub-grade, in accordance with the requirements
of these specifications and codal provisions and in conformity with the lines, grades and cross-
sections shown on the drawings or as directed by the Engineer-in-Charge.

B-5.2 General Types

(a) Mechanical Stabilisation.
(b) Lime-Soil Stabilisation.
(c) Lime-Fly ash-Soil Stabilisation.
(d) Cement Stabilisation.
(e) Bitumen Stabilisation.

B-5.3 Construction operations

B-5.3.1 General :
Stabilised soil sub-bases shall be constructed by mix-in place method of construction or as
otherwise approved by the Engineer-in-Charge. Manual mixing shall be permitted only where the
width of layer is not adequate for mechanical operations and where the machineries are not readily
available. The items incorporated in the schedule of rates are prepared on the basis of works done
manually.
The plant used for mix-in place construction shall be capable of pulverizing the soil to specified
degree to the full thickness of the layer being processed, and of so achieving the desired degree of
mixing and uniformity of the stabilised material. If so desired by the Engineer-in-Charge, trial runs
with the plant shall be carried out to establish its suitability for work.
The thickness of any layer to be stabilised shall be not less than 100 mm. when compacted.
The thickness may be as high as 200 mm. provided the plant used is accepted by the Engineer-in-
Charge as capable of meeting the specification requirements.

B-5.3.2 Mix-in place method of construction

Before deploying the plant, the soil after it is made free of undesirable vegetation or other
deleterious matter shall be spread uniformly on the prepared sub-grade in a quantity sufficient to
achieve the desired compacted thickness of the stabilized layer. Where single-pass equipment is to
be employed, the soil shall be lightly rolled as per direction of the Engineer-in-Charge.
The plant used shall either be of single-pass or multiple-pass type. The mixers shall be equipped
with an appropriate device for controlling the depth of processing and the mixing blades shall be
maintained or reset periodically so that the concrete depth of mixing is obtained at all time.
With single-pass equipment the forward speed of the machine shall be so selected in relation to the
rotor-speed that the required degree of mixing, pulverization and depth of processing is obtained.In
multi-pass processing, the soil on the prepared embankment shall be pulverized to the required
depth with successive passes of the plant and the moisture content adjusted to be within prescribed
limits mentioned herein after. The blending or stabilized material shall then be spread uniformly
and mixing continued with successive passes until the required depth and uniformity of processing
has been obtained.

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The mixing plant shall be so set that it cuts slightly into the edge of the adjoining lane processed
previously so as to ensure that all the material forming a layer has been properly processed for the
full width.In case of manual mixing, it shall be ensured to the satisfaction of the Engineer-in-
Charge that there has been a uniform mixing of the various ingredients to the full depth of the layer.

B-5.3.3 Degree of pulverization

For effective stabilization, the soil shall be pulverized to the extent as per codal provision for
different stabilization works.

B-5.3.4 Moisture content for compaction

For mechanical stabilization, moisture content at compaction shall be within the range 1 percent
above to 2 percent below the optimum moisture content corresponding to IS:2720 (Part VIII).
The moisture content shall be adjusted during mixing operation (making allowance for evaporation
losses) and checked before rolling starts.

B-5.3.5 Rolling
Immediately after spreading, grading, and leveling of the mixed material, compaction shall be
carried out with 8 to 10 tonne smooth wheel rollers or other approved plant, preceded by a few
passes of lighter rollers if necessary. Rolling shall commence at edges and progress forwards the
centre, except at super elevated portions where it shall commence at the inner edge and progress
towards outer. During rolling the surface shall be frequently checked for grade and camber and any
irregularities corrected by loosening the material and removing or adding fresh material.
Compaction shall continue until the density achieved is least 98 percent of the maximum dry
density for the material determined in accordance with IS: 2720 (Part VIII).
The final surface shall be well closed, free from movement under compaction plant, and any
compaction planes, ridges, cracks or loose material. All loose segregated or otherwise defective
areas shall be made good to the full thickness of the layer and re-compacted.

B-5.3.6 Surface finish and Quality control of work

The surface finish of the construction shall conform to the requirements for “quality control” for
Road works.

B-6 GRANULAR SUB-BASE

B-6.1 Description :
This work shall consist of laying and compacting well-graded material on prepared sub-grade in
accordance with the requirements of these specifications. The material shall be laid in one or more
layers as sub-base or lower sub-base and upper sub-base as necessary according to lines, grades and
cross sections shown on the drawings or as directed by the Engineer-in-Charge.

B-6.2 Materials
The material to be used for the work shall be natural sand, moorum, gravel, crushed stone, crushed
slag, crushed concrete, brick metal, laterite, kankar etc. or combinations thereof depending upon the
grading required. The mixed material shall be free from organic or other deleterious constituents
and conform to one of the three grading given in Table B 6.2-1 & B 6.2-2.

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B-6.3 Physical requirements
The fraction of material passing 22.4mm sieve shall give a CBR value as specified in Table above
or more as specified in the contract, when tested in accordance with IS: 2720 (Part XVI) after
preparing the samples at maximum dry density and optimum moisture content corresponding to IS:
2720 (Part VII) and soaking the same in water for 4 days.
Table B 6.2-1: GRADING FOR CLOSE-GRADED GRANULAR SUB-BASE MATERIALS
Percent by weight passing the IS sieve
IS Sieve Designation
Grading I Grading II Grading III
75.0 mm. 100 - -
53.0 mm. 80-100 100 -
26.5 mm. 55-90 70-100 100
9.50 mm. 35-65 50-80 65-95
4.75 mm. 25-55 40-65 50-80
2.36 mm. 20-40 30-50 40-65
0.425 mm. 10-25 15-25 20-35
0.075 mm. 3-10 3-10 3-10
CBR Value (Minimum) 30% 25% 20%
Table B 6.2-2: GRADING FOR COARSE-GRADED GRANULAR SUB-BASE MATERIALS
Percent by weight passing the IS sieve
IS Sieve Designation
Grading I Grading II Grading III
75.0 mm. 100 - -
53.0 mm. - 100 -
26.5 mm. 55-75 50-80 100
9.50 mm. - - -
4.75 mm. 10-30 15-35 25-45
2.36 mm. - - -
0.425 mm. - - -
0.075 mm. <10 <10 <10
CBR Value (Minimum) 30% 25% 20%
Note :
The material passing 425 micron sieve for all the three grading when tested according is IS: 2720 (Part V) shall have
liquid limit and plasticity index of not more than 25 per cent and 6 per cent respectively.
B-6.4 Strength of Sub-base
It shall be ensured prior to actual execution that the material to be used in the sub-base satisfies the
requirements of CBR and other physical requirements when compacted and finished.
When directed by the Engineer-in-Charge, this shall be verified by performing CBR tests in the
laboratory as required on specimens remoulded at field density, and moisture content and any other
tests for the quality of materials, as may be necessary.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-6.5 Construction operations

B-6.5.1 Preparations of Sub-grade

Immediately prior to the laying of sub-base, the sub-grade already finished shall be prepared by
removing all vegetation and other extraneous matter, lightly sprinkled with water; if necessary and
rolled with two passes of 8-10 tonne smooth wheeled roller.

B-6.5.2 Spreading and compaction

The sub-base material of specified grading shall be spread on the prepared sub-grade with the help
of a drag spreader, motor grader or other approved means such as manually when permitted by the
Engineer-in-Charge.
When the sub-base material consists of combination of materials mentioned in Clause B-6.2,
mixing shall be done mechanically by the mix-in-place method.
Manual mixing shall be permitted only where the width of laying is not adequate for mechanical
operations, as in small-sized jobs. The equipment used for mix-in-place construction shall be a
rotavator or similar approved equipment capable of mixing the material to the desired degree. If so
desired by the Engineer-in-Charge, trial runs with the equipment shall be carried out to establish its
suitability for the work.
Moisture content of the loose material shall be checked in accordance with IS: 2720 (Part II) and
suitably adjusted by sprinkling additional water from a hose line, truck mounted water tank or other
approved means so that at the time of compaction it is from 1 per cent above to 2 per cent below the
optimum moisture content corresponding to IS: 2720 (Part VIII). While adding water due
allowance shall be made for evaporation losses. After water has been added the material shall be
processed by mechanical or other approved means if so directed by the Engineer-in-Charge until
the layer is uniformly wet.
Immediately thereafter, rolling shall start. If the thickness of the compacted layer does not exceed
100 mm, a smooth wheeled roller of 8 to 10 T weight may be used. For a compacted single layer up
to 225 mm the compaction shall be done with the help of a vibratory roller of minimum 8 to 10 T
static weight with plain drum or pad foot-drum or heavy pneumatic tyred roller of minimum 20 to
30 T weight having a minimum tyre pressure of 0.7 MN/m2 or equivalent capacity roller capable of
achieving the required compaction. Rolling shall commence at the lower edge and proceed towards
the upper edge longitudinally for portions having unidirectional cross fall and superelevation and
shall commence at the edges and progress towards the centre for portions having cross fall on both
sides.
Each pass of the roller shall uniformly overlap Rolling shall be continued till the density achieved
is at least 98% of the maximum dry density for the material determined as per IS: 2720 (Part VIII).
The surface of any layer of material on completion of compaction shall be well closed, free from
movement under compaction equipment and from compaction planes, ridges, cracks or loose
material. All loose segregated or otherwise defective area shall be made good to the full thickness
of layer and re-compacted.

B-6.5.3 Surface finish and quality control of work

The surface finish of construction shall conform to the requirements for “Quality Control for Road
Works”.

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B-6.5.4 Arrangement of Traffic
During the period of construction flow of traffic shall be maintained in the manner as stated in
“Arrangement for traffic during construction” under bituminous works.

B-6.6 Shoulder Construction

B-6.6.1 Description
This work shall consist of constructing shoulders (earthen/hard/paved) on either sides of the
pavement, in accordance with the requirements of these specification and in conformity with the
lines, grades and cross sections shown on the drawings or as directed by the Engineer-in-Charge.

B-6.6.2 Materials
Shoulder on either side of the road may be of selected earth/granular material/paved conforming to
requirements of embankment construction.

B-6.6.3 Size of shoulder

Shoulder (earth/hard/paved) dimensions shall be as per the drawing or as directed by the Engineer-
in-Charge.

B-6.6.4 Construction Operation

The sequence of operations shall be such that the construction of paved shoulder is done in layers
each matching the thickness of adjoining pavement layer. Only after a layer of pavement and
corresponding layers in paved and earth shoulder portion have been laid and compacted, the
construction of next layer of pavement and shoulder shall be taken up.
Where the materials in adjacent layers are different, these shall be laid together and the pavement
layer shall be compacted first. The corresponding layer in paved shoulder portion shall be
compacted thereafter, which shall be followed by compaction of each shoulder layer. The adjacent
layers having same material shall be laid and compacted together.
In all cases where paved shoulder have to be provided alongside of existing carriageway, the
existing shoulders shall be excavated in full width and to the required depth. Under no
circumstances, box cutting shall be done for construction of shoulders.
Compaction requirement of earthen shoulder shall be as per Table under Clause B-4.3.5. in the case
of bituminous courses, work on shoulder (earthen/hard/paved) shall start only after the pavement
course has been laid and compacted.
During all stages of shoulder (earth/hard/paved) construction, the required crossfall shall be
maintained to drain off surface water.
Regardless of the method of laying, all shoulder construction material shall be placed directly on
the shoulder. Any spilled material dragged on to the pavement surface shall be immediately
removed, without damage to the pavement, and the area so affected thoroughly cleaned.

B-6.6.5 Measurement for payments

Shoulder construction shall be measured as finished work in position in square meters.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-7 WATER BOUND MACADAM SUB-BASE / BASE COURSE

B-7.1 Description
Water bound macadam shall consist of clean, crushed aggregates mechanically interlocked by
rolling, and bonded together with screening, binding material where necessary and water laid on
properly prepared sub-grade / sub-base / base, or existing pavement, as the case may be and
finished in accordance with requirement of these specifications and in close conformity with the
lines, grades, cross sections and thickness as per approved drawings or otherwise directed by the
Engineer-in-Charge.
B-7.2 Materials
B-7.2.1 Coarse aggregate – General requirements
Coarse aggregates shall be either crushed or broken stone, crushed slag, over burnt (jhama) brick
aggregates, or one other naturally occurring aggregates such as kankar or laterite of suitable quality
(which shall be used in sub-base course only) as stated hereinafter and approved by Engineer-in-
Charge. The aggregates shall conform to the physical requirement set forth in Table B 7.2-1. The
type and size range of aggregate shall be specified in the contract.
Table B 7.2-1: PHYSICAL REQUIREMENTS OF COARSE AGGREGATES FOR WATER
BOUND MACADAM FOR SUB-BASE / BASE COURSE.
Sl. No. Test Test Method Requirements
(a) Los Angles Abrasion Value* IS: 2386 (Part 4) 40 per cent (max.)
or
Aggregate Impact Value* IS: 2386 (Part 4) or 30 per cent (max.)
IS: 5640**
(b) Combined Flakiness and Elongation IS: 2386 (Part I) 30 per cent (max.)
Indices (Total) ***
* Aggregates may satisfy requirements of either of the two tests.
** Aggregates like brick, metal, kankar and laterite which get softened in presence of water, shall be tested for
impact value under wet conditions in accordance with IS: 5640.
*** The requirement of flakiness index and elongation index shall be enforced only in the case of crushed broken
stone and crushed slag.
(a) Crushed or broken stone
When crushed or broken stone is specified as the coarse aggregate, it shall be hard, durable and free
from excess of flat, elongated, soft and disintegrated particles, dirt and other deleterious materials.
(b) Crushed slag
Crushed slag shall be made from air-cooled blast furnace slag. It shall be of angular shape,
reasonably uniform in quality and density and generally free from thin, elongated and soft pieces,
dirt or other deleterious materials. Crushed slag shall not weight less than 1120 kg per m3 and the
percentage of glossy material shall not be more than 20.
(c) Overburnt (Jhama) brick aggregate
Jhama brick aggregate shall be made out of overburnt bricks or brick bats and be free from dust and
other objectionable and deleterious materials.
(d) Laterite
Laterite shall be hard, compact, heavy and of dark colour. The light coloured sandy lateritie as well
as those containing clay shall be rejected.

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(e) Kankar
Kankar shall be tough, having opalescent features. It shall not contain any clay in the cavities
between nodules.
B-7.2.2 Grading requirements of coarse aggregates
The coarse aggregates shall conform to one of the Grading given in Table B 7.2-2, provided
however, the use of Grading I shall be restricted to sub-base courses only.
Table B 7.2-2: GRADING REQUIREMENT OF COARSE AGGREGATES.
Grading No. Size range Sieve designation Percent by weight passing
the sieve
125 mm 100
90 mm 90-100
1 90 mm to 45 mm 63 mm 25-60
45 mm 0-15
22.4 mm 0-5
90 mm 100
63 mm 90-100
2 63 mm to 45 mm 53 mm 25-75
45 mm 0-15
22.4 mm 0-5
63 mm 100
53 mm 95-100
3 53 mm to 22.4 mm 45 mm 65-90
22.4 mm 0-10
11.2 mm 0-5
Note :
The compacted thickness for a layer with Grade 1 shall be 100 mm while the compacted thickness of a layer with
Grade 2 and 3 shall be 75 mm.

B-7.2.3 Screenings
Screenings to fill voids in the coarse aggregate shall generally consist of the same material as the
coarse aggregate. However, where permitted, predominantly non-plastic material such as moorum
or gravel (other than rounded river borne material), may be used for this purpose provided liquid
limit and plasticity index of such material are below 20 and 6 respectively and fraction passing 75
micron sieve does not exceed 10 percent.
Screenings shall conform to the grading set forth in Table 7.2-3. Screenings of Type A shall be
used with coarse aggregates of Grading I of Table 7.2-2. Screening of Type A or B, as specified
shall be used with coarse aggregates of Grading II.
Table 7.2-3: GRADING FOR SCREENINGS
Percent by weight passing
Grading classification Size of screenings Sieve designation
the sieve
A 13.2 mm 13.2 mm 100
11.2 mm 95-100
5.6 mm 15-35
180 micron 0-10

B 11.2 mm 11.2 mm 100

5.6 mm 90-100
180 micron 15-35

The use of screenings shall be omitted in the case of soft aggregates such as brick metal, jhama,
kankar and laterite etc. as they are likely to get crushed to a certain extent under rollers.

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Section : 2 P.W. (Roads) Directorate
General Specification Schedule of Rates : 2008-2009

B-7.2.4 Binding material

Binding material to be used for water bound macadam as a filler material meant for preventing
raveling, shall comprise of a suitable material approved by the Engineer-in-Charge having
Plasticity Index (PI) value of less than 6 as determined in accordance with IS: 2720 (Part V).
Application of binding material may not be necessary, when the screenings used are of crushable
type such as moorum or gravel.

B-7.3 Construction operations

B-7.3.1 Preparation of base
The sub-grade/ sub-base/ base to receive the water bound macadam course shall be prepared to the
specified grade and camber and made free of dust and other extraneous materials. Any ruts or soft
yielding places shall be corrected in an approved manner and rolled until firm. Any sub-base/base
surface irregularities when predominant shall be made good by providing appropriate type of
profile corrective course (levelling course).
As far as possible, laying water bound macadam course over an existing thick bituminous layer
may be avoided since it will cause problems of internal drainage of he pavement at the interface of
two courses. It is desirable to completely pick out the existing thin bituminous wearing course
where water bound macadam is proposed to be laid over it.
However, where the intensity of rain is low and the interface drainage facility is efficient, water
bound macadam can be laid over the existing thin bituminous surface by cutting 50 mm x 50 mm
furrows at an angle of 450 to the centre line of the pavement at 1.00 m intervals on the existing
road. The directions and depth of furrows shall be such that they provide adequate bondage and
also serve to drain water to the existing granular base course beneath the existing thin bituminous
surface.

B-7.3.2 Inverted Choke

If the water bound macadam is to be laid directly over the sub-grade without any other intervening
pavement course, a 25mm course of screenings (Grading B) or coarse sand shall be spread on the
prepared sub-grade before application of the coarse aggregates is taken up. In case of a fine sand or
silty or clayey sub-grade, it is advisable to lay 100 mm. insulating layer of screening or coarse sand
on top of fine grained soil, the gradation of which will depend upon whether it is intended to act as
a drainage layer as well. As a preferred alternative to inverted choke, appropriate geo-synthetics
performing functions of separation and drainage may be used over the prepared subgrade as
directed by the Engineer-in-Charge.

B-7.3.3 Spreading coarse aggregate

The coarse aggregate shall be spread uniformly and evenly upon the prepared sub-grade/ sub-base/
base to proper profile by using templates across the road about 6 m. apart in such quantities that the
thickness of each compacted layer is not more than 100 mm for Grading 1 and 75 mm. for Grading
2 and 3 as specified in Clause 7.2.2 above.
The spreading shall be done from stock piles along the side of the roadway. In no case shall the
aggregate be dumped in heaps directly on the surface prepared to receive the aggregate nor shall
hauling over loose or partially compacted base be permitted. No segregation of large or fine
aggregate shall be allowed and the coarse aggregate as spread shall be of uniform gradation with no
pocket of fine materials.
The surface of the aggregates spread shall be carefully checked with templates and all high or low
spots remedied by removing or adding aggregate as may be required. The surface shall be checked
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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
frequently with a straight edge while spreading and rolling so as to ensure a finished surface as per
approved drawing.
The coarse aggregate shall not normally be spread more than 3 days in advance of the subsequent
construction operations.

B-7.3.4 Rolling
Immediately following the spreading of the coarse aggregate, rolling shall be stated with three
wheeled power rollers of 8 to 10 Tonnes capacity or tandem or vibratory rollers of approved type.
The type of roller to be used shall be approved by the Engineer-in-Charge based on trial run.
Except on super elevated portions where the rolling shall proceed from inner edge to the outer,
rolling shall begin from the edges gradually progressing towards the centre. First the edge/edges
shall be compacted with roller running forward and backward. The roller shall then move inwards
parallel to the centre line of the road, in successive passes uniformly lapping preceding tracks by at
least one half width.
Rolling shall be discontinued when the aggregates are partially compacted with sufficient void
space in them to permit application of screenings. However, in the case of crushed aggregates like
brick metal, laterite, kankar etc., where screenings are not to be applied, compaction shall be
continued until the aggregates are thoroughly keyed. During rolling, slight sprinkling of water may
be done, if necessary. Rolling shall not be done when the sub-grade is soft or yielding or when it
causes wave like motion in the sub-grade or sub-base course.
The rolled surface shall be checked transversely and longitudinally with templates any irregularities
corrected by loosening the surface, adding or removing necessary amount of aggregate and re-
rolling until the entire surface conforms to desired camber and grade. In no case shall the use of
screenings be permitted to make up depressions.
Materials which get crushed excessively during compaction or becomes segregated shall be
removed and replaced with suitable aggregates.

B-7.3.5 Applications of screenings

After completion of rolling of the coarse aggregate as per Clause B-7.3.4 above, screenings shall be
applied gradually over the surface to completely fill the interstices. These shall not be damp or wet
at the time of application. Dry rolling shall be done while the screenings are being spread, so that
vibrations of the roller cause them to settle into the voids of the coarse aggregate. The screenings
shall not be dumped in piles but be spread uniformly in successive thin layers either by the
spreading motion of hand shovels or by mechanical spreaders, or directly from trucks with suitable
grit spreading arrangement. Trucks operating for spreading the screenings shall be so driven as not
to disturb the coarse aggregate.
The screenings shall be applied at a slow and uniform rate (in three or more applications) so as to
ensure filling of all voids. This shall be accompanied by dry rolling and brooming with mechanical
brooms, hand brooms or both. In no case shall the screening be applied so fast and thick as to form
cakes or ridges on the surface in such a manner as would prevent filling of voids or prevent the
direct bearing or roller on the coarse aggregate. These operations shall continue until no more
screenings can be forced into the voids of the coarse aggregate.
The spreading, rolling and brooming of screenings shall be carried out in only such lengths of the
road which could be compacted within one day’s operation.

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Section : 2 P.W. (Roads) Directorate
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B-7.3.6 Sprinkling of water and grouting

After the screenings have been applied, the surface shall be copiously sprinkled with water, swept
and rolled. Hand broom shall be used to sweep the wet screenings into voids and distribute them
evenly. The sprinkling, sweeping and rolling operations shall be continued, with additional
screenings applied as necessary, until the coarse aggregate has been thoroughly keyed, well bonded
and firmly set in its full depth and a grout has been formed of screenings. Care shall be taken to
see that the base or sub-grade does not get damaged due to the addition of excessive quantities of
water during construction.

B-7.3.7 Application of binding material

After the application of screenings in accordance with paragraphs above, the binding material
where it is required to be used (as per conditions noted in Clause B-7.2.4 above) shall be applied
successively in two or more thin layers at a slow and uniform rate. After each application, the
surface shall be copiously sprinkled with water, the resulting slurry swept in with hand brooms or
mechanical brooms to fill the voids properly, and rolled during which water shall be applied to
wheels of the rollers if necessary to wash down the binding material sticking to them. These
operations shall continue until the resulting slurry after fillings or voids, forms a wave ahead of the
wheels of the moving roller.

B-7.3.8 Setting and drying

After final compaction of water bound macadam course, the pavement shall be allowed to dry over
night. Next morning hungry spots shall be filled with screenings or binding material as directed,
lightly sprinkled with water if necessary and rolled. No traffic shall be allowed on the road until the
macadam has set.
The Engineer-in-Charge shall have the discretion to stop hauling traffic from using the completed
water bound macadam course, if in his opinion it would cause excessive damage to the surface. The
compacted WBM course should be allowed to dry completely and set before the next pavement
course is laid over it.

B-7.3.9 Reconstruction of defective macadam

The finished surface of water bound macadam shall conform to the tolerance of surface regularity
as prescribed in Clause 9.2.1.3. However, where the surface irregularity of the course exceeds the
tolerances or where the course is otherwise defective due to sub-grade soil mixing with the
aggregates, the course to its full thickness shall be scarified over the affected area, reshaped with
added material or removed and replaced with fresh material as applicable and re-compacted. In no
case shall depressions be filled up with screenings or binding material.

B-7.3.10 Surface finish & Quality control of work

The surface finish of construction shall conform to the requirements for “Quality Control for Road
Works” as detailed in Clause B-9.2 Control on the quality of materials and works shall be exercised
by the Engineer-in-Charge in accordance with Clause B-9.2.

B-7.3.11 Arrangement for traffic

During the period of construction the flow of traffic shall be maintained as detailed in Clause B-9.1.

B-7.3.12 Measurement for payment:

The measurement will be in square meter of actually finished area.

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B-8 WET MIX MACADAM SUB-BASE / BASE COURSE

B-8.1 Description :
This work shall consist of spreading and compacting clean crushed graded aggregate and granular
material premixed with water to a dense mass on a prepared sub-grade / sub-base / base or existing
pavement as the case may be in accordance with specification. The material shall be laid in one or
more layers as necessary to lines, grades and cross sections as directed by the Engineer-in-Charge.
The thickness of a single compacted wet mix layer shall not be less than 75 mm. when vibrating or
other approved types of compacted equipment are used, the compacted depth of a single layer of
the sub-base course may be increased to 200 mm upon approval of the Engineer-in-Charge.
Table B-8.1-1 Physical Requirements of Coarse Aggregate for Wet Mix Macadam for Sub-
Base/Base Courses.
Test Test Method Requirements

(a) * Los Angles Abrasion Value IS: 2386 (Part 4) 40 per cent Max.
or
*Aggregate Impact Value IS: 2386 (Part 4) or IS: 5640 30 per cent Max.

(b) Combined Flakiness and Elongation Indices (Total) IS: 2386 (Part I) 30 per cent Max.

* Aggregate may satisfy requirements of either of the two tests.

** To determine this combined proportion, the flaky stone from a representative sample should first be separated
out. Flakiness index is weight of flaky stone metal divided by weight of stone sample. Only the elongated
particles by separated out from the remaining (non-flaky) stone metal. Elongation index is weight of elongated
particles divided by total non-flaky particles. The value of flakiness index and elongation index so found are
added up.

B-8.2 Grading requirements of Aggregates for Wet Mix Macadam

The final gradation approved within the limits shown in Table B-8.2-1 shall be well graded from
coarse to fine and shall not vary from the lower limit on one sieve to the higher limit on the
adjacent sieve or vice versa.
Table B-8.2-1: Grading requirements of aggregates for Wet Mix Macadam
Sieve designation Percent by weight

53 mm 100
45 mm 95-100
26.5 mm -
22.4 mm 60-80
11.2 mm 40-60
4.75 mm 25-40
2.36 mm 15-30
600 micron 8-22
75 micron 0-8

Plasticity Index (P.I.) value of materials finer than 425 micron shall not exceed 6.

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Section : 2 P.W. (Roads) Directorate
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B-8.3 Construction operations:

B-8.3.1 Provision of Lateral confinement of aggregates

Before starting with Wet Mix Macadam construction, necessary arrangements should be made for
the lateral confinement of wet mix. This shall be done by laying materials in adjoining shoulders
alongwith that of Macadam layer.

B-8.3.2 Preparation of mix

Wet Mix Macadam shall be prepared in an approved mixing plant of suitable capacity having
provision for controlled addition of water and forced / positive mixing arrangement like pug mill or
span type mixer of concrete batching plant. For small quantity of wet mix work, the Engineer may
permit mixing to be done in concrete mixers.
Optimum moisture for mixing shall be determined in accordance with IS: 2720 (Part VIII) after
replacing the aggregate fraction retained on 22.4 mm. sieve with materials of 4.75 mm to 22.4 mm
size. While adding water, due allowance should be made for evaporation losses. However, at the
time of compaction, water in the wet mix should not vary from the optimum value by more than
agreed limits. The mixed material should be uniformly wet and no segregation should be permitted.

B-8.3.3 Spreading of mix

Immediately after mixing, the aggregates shall be spread uniformly and evenly upon the prepared
sub-grade / sub-base / base in required quantities. In no case should these be dumped in heaps
directly on the area where these are to be laid nor shall their hauling over a partly completed stretch
be permitted.
The mix may be spread either by power finisher or motor grader. For portions where mechanical
means cannot be used, manual means as approved by the Engineer shall be used. The motor grader
shall be capable of spreading the material uniformly all over the surface. Its blade shall have
hydraulic control suitable for initial adjustment and maintaining the same so as to achieve the
specified slope and grade.
The surface shall be carefully checked with templates and all high or low spots remedied by
removing or adding aggregate as may be required. No segregation of larger and fine particles
should be allowed. The aggregates as spread should be of uniform gradation with no pockets of fine
materials.

B-8.3.4 Compaction
After the mix has been laid to the required thickness, grade and cross-fall / camber the same shall
be uniformly compacted, to the full depth with suitable roller. If the thickness of single compacted
layer does not exceed 100 mm, a smooth wheel roller of 80 to 100 KN weight may be used. For a
compacted single layer upto 200 mm, the compaction shall be done with the help of vibratory roller
of minimum static weight of 80 to 100 KN or equivalent capacity. The speed of the roller shall not
exceed 5 Km/h. The rolling shall be done as per standard procedure.
Rolling shall be continued until the specified density is achieved, or where no density is specified,
until there is no further movement under the roller.
After completion, the surface of any finished layer shall be well closed, free from movement under
compaction equipment or any compaction planes, ridgers, cracks and loose material. All loose,
segregated or otherwise defective areas shall be made good to the full thickness of the layer and re-
compacted.
After final compaction of wet mix macadam course, the road shall be allowed to dry for 24 hours.

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P.W.(Roads) Directorate Section : 2
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B-8.3.5 Rectification of Surface Irregularity
Where the surface irregularity of the wet mix macadam course exceeds the permissible tolerances
or where the course is otherwise defective due to sub-grade soil getting mixed with the aggregates,
the full thickness of the layer shall be scarified over the affected area, reshaped with added
premixed material or removed and replaced with fresh premixed material as applicable and re-
compacted as stated above. The area treated in the aforesaid manner shall not be less than 5 m long
and 2 m wide. In no case shall depressions be filled up with unmixed and ungraded material or
fines.

B-0 TRAFFIC ARRANGEMENT & QUALITY CONTROL

B-9.1 ARRANGEMENT FOR TRAFFIC DURING CONSTRUCTION

B-9.1.1 General :
The Contractor shall at all time carry out work on the highway in a manner creating least
interference to the flow of traffic while consistent with the satisfactory execution of the same. For
all works involving improvements to the existing highway, the contractor shall, in accordance with
directions of the Engineer-in-Charge, provide and maintain, during the execution of the work, a
passage for traffic either along a part of the existing carriage way under improvement, or along a
temporary diversion constructed close to the highway.

B-9.1.2 Passage of Traffic along a part of the Existing Carriageway under Improvement
This method shall be adopted where, in the opinion of the Engineer-in-Charge, the improvement
works, namely widening / strengthening of the existing pavement or reconstruction / repairs to
cross-drainage work, could be carried out on part widths at a time and the traffic could
simultaneously be passed without under delay and difficulty on the other part. The road shoulder
shall be dressed and brought in line with the pavement and maintained throughout the duration of
the work to the satisfaction of the Engineer-in-Charge, where work is in progress in continuous in
long stretches, passing places, at least 20 m long and 6 m wide, inclusive of the width of existing
carriageway, shall be provided half to one km intervals as directed by the Engineer-in-Charge.
Extra treatment to shoulder, where necessary, shall be given as ordered by the Engineer-in-Charge.

B-9.1.3 Passage of Traffic along a Temporary Diversion :

If in the opinion of the Engineer-in-Charge it is not possible to pass the traffic on part width of the
carriageway for any reason, a temporary diversion close to the highway shall be constructed as
directed. It shall be paved with locally available materials such as hard moorum, gravel, brick or
stone metal to the specified thickness and provided with bituminous surfacing where directed. In all
cases, the alignment, gradients and surface type of the diversion, including its junctions, shall be
approved by the Engineer-in-Charge before the highway to be declared is closed to traffic. At cross
drainage point, the contractor shall provide temporary crossings for the diversion according to the
designs approved by the Engineer-in-Charge.

B-9.1.4 Traffic safety and control

The contractor shall take all necessary measures for the safety of traffic during construction and
provide, erect and maintain such barricades, signs, flags, lights and flagmen as may be required by
the Engineer-in-Charge for the proper information and protection of traffic approaching or passing
through the section of the highway under improvement. Before taking up any construction, an

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Section : 2 P.W. (Roads) Directorate
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agreed phased programme for the diversion of traffic on the highway shall be drawn up in
consultation with the Engineer-in-Charge.
The barricades erected on either side of the carriageway / portion of the carriageway closed to
traffic, shall be strong design to resist violation, and painted with alternate black and white stripes.
Red lanterns or warning lights or similar type shall be mounted on the barricades at night and kept
it throughout from sunset to sunrise.
At the points where traffic is to deviate from its normal path (whether on temporary diversion or
part width of the carriageway) the channel for traffic shall be clearly marked with the aid of
pavement markings, painted drums or a similar device to the directions of the Engineer-in-Charge.
At night the passage shall be delineated with lanterns or other suitable light source.
One-way traffic operation shall be established whenever the traffic is to be passed over part of the
carriageway inadequate for two-lane traffic. This shall be done with the help of flagmen kept
positioned on opposite sides during all hours. For regulation of traffic, the flagmen shall be
equipped with red and green flags lanterns / light.
On both sides, suitable regulatory / warning signs shall be installed for the guidance of road users.
On each approach at least two signs shall be put up, one close to the point where transition of
carriageway begins and the other 120 m away. The signs shall be of approved design and of
reflecting type, if so directed.

B-9.1.5 Maintenance of Diversions and Traffic control Devices

Signs, light barricades and other traffic control devices, as well as the riding surface of diversions
shall be maintained in satisfactory condition till such time as they are required as directed by the
Engineer-in-Charge. The temporary traveled way shall be kept free of dust by frequent applications
of water, if necessary.

B-9.1.6 Measurement for payments

All arrangements for traffic during construction including maintenance thereof but excluding initial
dressing and / or extra treatment to shoulders and construction of temporary diversions shall be
considered as incidental to the works and contractor’s responsibility.
Construction of temporary diversions, initial dressing of the shoulders and extra paving at passing
places shall, however, be paid for as provisional sum.

B-9.2 QUALITY CONTROL FOR ROAD WORKS

B-9.2.1 Control of Alignment and surface regularity

B-9.2.1.1 General
All works performed shall conform to the lines, grades, cross section and dimensions shown on the
drawings or as directed by the Engineer-in-Charge subject to the permitted tolerances described
hereinafter.
B-9.2.1.2 Horizontal alignments
Horizontal alignments shall be reckoned with respect to the centre line of the carriageway as shown
on the drawings. The edges of the carriageway as constructed shall be corrected within a tolerance
of ± 10mm there from. The corresponding tolerance for edges of the roadway and lower of
pavement shall be ± 25 mm.

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B-9.2.1.3 Surface levels
The levels of the sub-grade and different pavement courses as constructed shall not vary from
those calculated with reference to the longitudinal and cross-profile of the road shown on the
drawings or as directed by the Engineer-in-Charge, beyond the tolerances mentioned in Table B
9.2-1.
Table B 9.2-1: TOLERANCES IN SURFACE LEVELS
Sl. No. Items Tolerance
1. Sub-grade: + 20 mm / - 25 mm

2. Sub-base:

(a) Flexible pavement + 10 mm / - 20 mm

(b) Concrete pavement + 6 mm / -10 mm
(Dry lean concrete or Rolled concrete)
3. Base-course for flexible pavement

(a) Bituminous course ± 6 mm

(b) Other than bituminous

(i) Machine laid. ± 10 mm

(ii) Manually laid. ± 15 mm

4. Wearing course for flexible pavement

(a) Machine laid ± 6 mm

(b) Manually laid. ± 10 mm

5. Cement concrete pavement + 5 mm / - 6 mm*
* This may not exceed 8mm at 0-30cm from the edges.
Provided, however, that the negative tolerance for wearing course shall not be permitted in
conjunction with the positive tolerance for base course if the thickness of the former is thereby
reduced by more than 6mm for flexible pavements and 5 mm for concrete pavements.

B-9.2.1.4 Surface regularity of pavement courses

The surface regularity of completed sub-bases, base courses and wearing surfaces both in
longitudinal and transverse directions shall be within the relevant tolerances stated in Table 9.2-2.
The longitudinal profile shall be checked with a 3 m long straight edge/ moving straight edge, at the
middle of each traffic lane along a line parallel to the centre line of the road. The transverse profile
shall be checked with a set of three camber boards at intervals of 10 m.
The maximum allowable difference between the road surface and underside of a 3 m straight-edge
when placed parallel with, or at right angles to the centre line of the road at points decided by the
Engineer-in-Charge shall be:
For pavement surface (bituminous and cement concrete) 3 mm
For bituminous base courses 6 mm
For granular sub-base/ base courses 8 mm
For sub-base under concrete pavements 10 mm

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Section : 2 P.W. (Roads) Directorate
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Table 9.2-2 : MAXIMUM PERMITTED NUMBER OF SURFACE IRREGULARITIES

Surfaces of lay-bys, service areas and all
Surfaces of carriageways and paved shoulder
bituminous base course
Irregularity 4 mm 7 mm 4 mm 7 mm
Length (m) 300 75 300 75 300 75 300 75

National
Highways/ 20 9 2 1 40 18 4 2
Expressways*

Road of lower
40 18 4 2 60 27 6 3
category*
* Category of each section of road as described in the Contract.

B-9.2.1.5 Rectification
Where the surface regularity of sub-grade and the various pavement courses fall outside the
specified tolerances, the Contractor shall be liable to rectify these in the manner described below
and to the satisfaction of the Engineer-in-Charge.
a) Sub-grade: Where the surface is high, it shall be trimmed and suitably compacted. Where
the same is low, the deficiency shall be corrected by adding fresh material.
The degree of compaction and the type of material to be used shall conform to the
requirement of embankment construction.
b) Granular and Mechanically stabilized sub-base: Same as at (i) above except the degree
of compaction and the type of material to be used shall conform to the requirements of
construction of Granular sub-base and mechanically stabilized soil sub-base.
c) Cement/Lime stabilized soil sub-base: For cement / lime treated materials where the
surface is high, the same shall be suitably trimmed while taking care that the material below
is not disturbed due to this operation. However, where the surface is low, the same shall be
corrected as described here in below.
For the cement treated material when the time elapsed between detection of irregularity and
the time of mixing of the materials is less than 2 hours, the surface shall be scarified to a
depth of 50 mm. supplemented with freshly mixed material as necessary and re-compacted
to the relevant specification. When this time is more than 2 hours, the full depth of the layer
shall be removed from the pavement and replaced with fresh material to specification. In
either case, the area treated shall not be less than 5 m long and 2 m wide. This shall also
apply to lime treated material except that the time criterion shall be 3 hours instead of 2
hours.
d) Water Bound Macadam / Wet Mix Macadam Base / Sub-base: Where the surface is
high or low, the top 75 mm shall be scarified, re-shaped with added material as necessary
and re-compacted to the required compaction for WBM/Wet Mix Macadam. The area
treated at a place shall not be less than 5 m long and 2 m wide.
e) Bituminous construction: For bituminous construction, other than wearing course, where
the surface is low, the deficiency shall be corrected by adding fresh material over a suitable
tack coat if necessary and re-compacting to specifications. Where the surface is high, the
full depth of the layer shall be removed and replaced with fresh material and compacted to
specifications.
For wearing course, where the surface is high or low, the full depth of the layer shall be
removed and replaced with fresh material and compacted to specifications. In all cases

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where the removal and replacement of bituminous layer is involved, the area treated shall
not be less than 5 m in length and not less than 3.5 m in width.

B-9.3 QUALITY CONTROL TESTS DURING CONSTRUCTION

B-9.3.1 General
The materials supplied and the works carried out by the Contractor shall conform to the
specifications prescribed in the preceding Clauses.
For ensuring the requisite quality of construction, the materials and works shall be subjected to
quality control tests, as described hereinafter, by the Engineer-in-Charge. The testing frequencies
set forth are the desirable minimum and the Engineer-in-Charge shall have the full authority to
carry out tests as frequently as he may deem necessary to satisfy himself that the materials and
works comply with the appropriate specifications. However the number of tests recommended in
Tables under Clauses B-9.3 and B-9.3 may be reduced at the discretion of the Engineer-in-Charge.
Test procedures for the various quality control tests are indicated in the respective sections of
specification or for certain tests within this section. Where no specific testing procedure is
mentioned for quality control, tests shall be carried out as per the prevalent accepted engineering
practice to the direction of the Engineer-in-Charge.
B-9.3.2 Tests on Earthwork, Subgrade Construction & Cut formation
I. Borrow material :
(i) Sand Content [IS: 2720 (Part IV)] : Two tests per 3000 m3 of soil.
(ii) Plasticity Test [IS: 2720 (Part V)] : Each type to be tested 2 tests per
3000 m3 of soil.
(iii) Density Test [IS: 2720 (Part VIII)] : Each soil type to be tested, 2 tests
per 3000 m3 of soil.
(iv) Deleterious Content Test : As and when required by the
[IS: 2720 (Part XXVII)] Engineer-in-Charge.
(v) Moisture Content Test : One test for every 250 m3 of soil
[IS: 2720 (Part II)]
(vi) CBR Test on materials to be : At least one test for every 3000 m3
incorporated in the sub-grade or closer as and when required by
on soaked/un-soaked Samples the Engineer-in-Charge.
{IS: 2720 (Part XVI)]
B-9.3.3 Compaction control
Control shall be exercised by taking at least one measurement of density for each 1000 m2 of
compacted area, or closer as required to yield the minimum number of test results for evaluating a
day’s work on statistical basis. The determination of density shall be in accordance with IS: 2720
(Part XXVIII). Test locations shall be chosen only through random sampling techniques. Control
shall not be based on the result of any one test but on the mean value of a set of 5-10 density
determinations. The number of tests in one set of measurements shall be 6 as long as it is felt that
sufficient control over borrow material and the method of compaction is being exercised. If
considerable variations are observed between individual densities, results the minimum number of
tests in one set of measurement shall be increased to 10. The acceptance criteria shall be subject to
the condition that the mean dry density is not less than:

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Section : 2 P.W. (Roads) Directorate
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1.65
Specified density + 1.65 - x Standard deviation
(No. of samples)0.5

However, for earthwork in shoulders (earthen) and in the subgrade, at least one density
measurement shall be taken for every 500 m2 of the compacted area provided further that the
number of tests in each set of measurements shall be at least 10. In other respects the control shall
be similar to that described earlier.

B-9.3.4 Tests on non-bituminous Sub-bases and Bases

The tests and their frequencies for the different types of bases and sub-bases shall be as given in
Table B 9.3-1. The evaluation of density results for compaction control shall be on lines similar to
those set out in Clause 9.3.2 above.
Table B 9.3-1: CONTROL TESTS AND THEIR FREQUENCY FOR SUB-BASES AND BASES
(EXCLUDING BITUMEN BOUND BASES)
Sl. No. Type of Construction Test Frequency (Minimum)
1. Granular and (i) Gradation One test per 200 m3
mechanically
stabilised soil sub- (ii) Atterberg’s limit. -do-
bases
(iii) Deleterious constituents. As required.

(iv) CBR test on a set of 3 As required.

specimens

(v) Moisture content prior to One test per 250 m2

compaction
(vi) Density of compacted layer One test per 500 m2

2. Lime/Cement (i) Quality of lime/cement One test for each consignment subject to a
stabilised soil sub-base minimum of one test per 5 tonnes.

(ii) Lime/Cement content Regularly through procedural checks.

(iii) Degree of pulverization Periodically as considered necessary

(iv) Moisture content prior to One test per 250 m2

compaction

(v) Density of compacted layer One test per 500 m2

(vi) Deleterious constituents As required

(vii) CBR test on a set of 3 As required

specimens

3. Water Bound (i) Aggregate Impact Value One test per 200 m3 of aggregate
Macadam and Wet
Mix Macadam (ii) Grading One test per 100 m3 of aggregate.

(iii) Flakiness Index & One test per 200 m3 of aggregate.

Elongation Index.
(iv) Atterberg’s limit of binding One test per 25 m3 of binding material.
material (for WBM only).

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P.W.(Roads) Directorate Section : 2
Schedule : 2008-2009 General Specification
Sl. No. Type of Construction Test Frequency (Minimum)
(v) Atterberg’s limit of portion One test per 100 m3 of aggregate.
of aggregate passing 425
micron sieve.
One test per 500 m2
(vi) Density of compacted of
layer (For WMM only)

B-9.3.5 Tests on Bituminous Constructions

The tests and their frequencies for the different types of bases and sub-bases shall be as given in
Table B 9.3-2.
The acceptance criteria for tests on density and Marshall Stability shall be subject to the condition
that the mean value is not less than the following:

1.65
Specified value + 1.65 - x Standard deviation
(No. of samples)0.5

Table B 9.3-2: CONTROL TESTS AND THEIR FREQUENCIES FOR BITUMINOUS

CONSTRUCTION WORKS.
Sl. No. Type of Construction Test Frequency
(Minimum)
1. Prime coat, (i) Quality of binder Number of samples per lot & tests as per
Tack coat IS:73 IS:217 & IS:8887.
&
Fog spray (ii) Binder temperature for At regular close intervals.
application.

(iii) Rate of spread of binder One test per 500 m2 & not less than 2 tests
per day.
2. Seal Coat (i) Quality of binder. Two samples per lot.
&
Surface Dressing (ii) Aggregate Impact Value/ One test per 50 m3 of aggregate.
Los Angeles abrasion
value.

(iii) Flakiness Index and - do -

Elongation Index

(iv) Grading of aggregates. One test per 25 m3 of aggregate.

(v) Temperature of binder at At regular close intervals.

application.

(vi) Rate of spread of One test per 500 m2 of work but not less
materials. than 2 tests/day.

(vii) Water absorption. Initially one set of 3 representative

specimens for each source of supply.
Subsequently when warranted by changes
in the quality of aggregates.

(viii) Stripping Value of - do -

aggregates.

(ix) Stone polishing Value. As required.

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Section : 2 P.W. (Roads) Directorate
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Sl. No. Type of Construction Test Frequency

(Minimum)
3. Open-graded premix (i) Quality of binder. Same as Sl. No. 2
Carpet
& (ii) Aggregate Impact Value/ - do -
Mix Seal surfacing Los Angeles abrasion
value.

(iii) Flakiness Index and - do -

Elongation Index

(iv) Grading of aggregates. - do -

(v) Temperature of binder at - do -

application.

(vi) Rate of spread of Regular control through checks of layer

materials. thickness.

(vii) Water absorption, Same as Sl. No. 2

Stripping Value of
aggregates.

(viii) Stone polishing Value. Same as Sl. No. 2.

(ix) Binder Content. One test per 500 m2 & not less than 2 tests
per day.
4. Bituminous Macadam (i) Quality of binder. Same as mentioned in Sl 1.

(ii) Aggregate Impact Value/ One test per 50-100 m3 of aggregates.

L.A Abrasion value.

(iii) Flakiness Index and -do-

Elongation Index.

(iv) Stripping Value and water Same as mentioned under Serial No.2.
absorption of aggregates.

(v) Grading of aggregates. Two test per day per plant both on the
individual constituents and mixed
aggregates from the dryer.

(vi) Binder content. Periodic, subject to minimum of two tests

per day per plant.

(vii) Control of temperature of At regular close intervals.

binder and aggregate for
mixing and of the mix at
the time of laying and
rolling.

(viii) Rate of spread of mixed Regular control through checks on layer

material. thickness.

(ix) Density of compacted One test per 250 m2 of area.

layer.
5. Bituminous (i) Quality of binder. Same as mentioned in Sl 1.
Penetration Macadam
& (ii) Aggregate Impact Value/ One test per 200 m3 of aggregates.

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P.W.(Roads) Directorate Section : 2
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Sl. No. Type of Construction Test Frequency
(Minimum)
Built up Spray grout L.A Abrasion value.

(iii) Flakiness Index and -do-

Elongation Index.

(iv) Stripping Value and water Same as mentioned under Serial No.2.
absorption of aggregates.

(v) Grading of aggregates. One test per 100 m3 of aggregates.

(vi) Temperature of binder at At regular close intervals.

application.

(vii) Rate of spread of binder. One test per 500 m2 of area.

6. Dense Bituminous (i) Quality of binder. As required.
Macadam,
Semi Dense (ii) Aggregate Impact Value / One test per 50 m3 of aggregates.
Bituminous Concrete Los Angeles Abrasion
& Value.
Bituminous Concrete
(iii) Flakiness Index and -do-
Elongation Index.

(iv) Stripping Value and Water Same as mentioned in Sl. No.2

Absorption of aggregates.

(v) Mix Grading. One set of test on individual constituents

and mixed aggregates from the dryer for
each 400 tones of mix subject to a
minimum of two tests per plant per day.

(vi) Stability of mix. For each 400 tones of mix produced, a set
of 3 Marshall specimens to be prepared and
tested for stability, flow value, density and
void content subject to a minimum of two
sets being tested per plant per day.

(vii) Control of temperature of At regular close intervals.

binder in boiler, aggregate
in dryer and mix at the
time of laying and rolling.

(viii) Control of binder content One test for each 400 tons of mix subject to
and gradation in the mix. a minimum of two tests per day per plant.

(ix) Rate of spread of mixed Regular control through checks on the

material. weight of mixed material and layer
thickness.

(x) Swell test on the mix. As required for bituminous concrete.

(xi) Density of compacted One test per 250 m2 of area.

layer.

7. Mastic Asphalt (i) Quality of binder. Same as mentioned in Sl. No.1.

(ii) Aggregate Impact Value / Same as mentioned in Sl. No.2.

Los Angeles Abrasion
Value.

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Sl. No. Type of Construction Test Frequency

(Minimum)

(iii) Flakiness Index and - do -

Elongation Index.

(iv) Stripping Value. - do -

(v) Grading of aggregates. Two tests per day per plant both on the
individual constituents and mixed
aggregates from dryer.

(vi) Control of temperature of At regular close intervals.

binder and aggregate for
mixing and mix at the time
of laying and compacting.

(vii) Control of binder content Periodic, subject to minimum of two tests

and gradation in the mix. per day per plant.

(viii) Rate of spread of mixed Regular control through checks of layer of

material. thickness.

(ix) Hardness number. One test for each 400 tones of mix subject
to a minimum of two tests per day.
8. Modified Binder (i) Softening Point. Initially on submission thereafter daily, if
blended at site. Weekly, if pre-blended.
(ii) Penetration at 25o & 4o C.

(iii) Elastic Recovery.

(iv) Ductility.

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B-10 SPECIFICATION OF BITUMINOUS BASE AND WEARING COURSE

B-10.1 Preparation of base for laying Bituminous Base and Wearing Courses
B-10.1.1 Scope
This work shall consist of preparing an existing granular or black-topped surface bituminous course
to specified lines, grade, and cross sections. The work shall be performed on such widths and
lengths as may be directed by the Engineer-in-Charge. The existing surface shall be firm and clean,
and treated with prime/ tack coat as shown in drawing or otherwise stated in the Contract.

B-10.1.2 Materials
(A) For Scarifying and relaying the granular base course :
The material used shall be coarse aggregate salvaged from scarification of the existing granular
base course supplemented by fresh coarse aggregates and screenings corresponding to water bound
macadam or wet mix macadam as the case may be.
(B) For patching Pot holes & Sealing Cracks :
For patching potholes, the materials used shall be coarse aggregate, screening, stone chippings,
bitumen, Cationic bitumen emulsion or a combination thereof as specified, conforming to the
quality requirements of these materials, depending upon the site requirements.
(C) For Profile corrective Course :
A profile Corrective course (levelling course) is essentially a pavement base material course for
correcting the existing pavement profile which has either lost its shape or has to be given a new
shape to meet the requirements of specified lines, grades and cross section. It shall be differentiated
from the strengthening course or other type of structural pavement course needed as a remedial
measure against inherent deficient and/or distressed pavement. It is meant to remove the
irregularity in the existing road profile only.

B-10.1.3 Profile Corrective Course

The type of material for use as profile corrective course shall be as shown on the drawings or as
directed by the Engineer-in-Charge. Where it is to be laid as part of the overlay/strengthening
course, the profile corrective course material shall be of the same specification as that of the
overlay/strengthening course. However, if provided as a separate layer, it shall be of the
specification and details given in the Contract drawings.
(a) Any high spots in he existing surface shall be removed by a milling machine or other
approved method, and all loose material shall be removed to the satisfaction of the
Engineer-in-Charge.
(b) Where the maximum thickness of profile corrective course will not be more than 40 mm,
the profile corrective course shall be constructed as an integral part of the overlay course. In
other cases, the profile corrective course shall be constructed as a separate layer, adopting
such construction procedures and using such equipments as approved by the Engineer-in-
Charge, to lay the specified type of material, to thickness and tolerance as specified, for the
course, to be provided.

B-10.1.4 Assessment of Profile corrective course :

Assessment of Profile corrective course shall be done by plotting the existing road profile by taking
levels at close intervals, the actual interval for levels required for the purpose may be decided by
the Engineer-in-Charge keeping in view the site situation in each individual case and

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superimposing over it the Profile corrective course profile which is derived from the final road
profile, which is decided and fixed from other consideration independent of profile corrective
course after accounting for the thickness of the stipulated superimposed courses over the Profile
corrective course. Profile corrective course profile shall not normally be fixed first and the final
road profile decided thereafter.

B-10.1.5 Construction operations

B-10.1.5.1 Preparing existing granular surface:
Where the existing surface is granular, all loose materials shall be removed and the surface lightly
watered where the profile corrective course to be provided as a separate layer. Where the profile
corrective course of bituminous material is to be laid over the existing granular surface, the latter
shall, after removal of all loose materials, be primed with as per the stipulations of prime coat over
granular base.
The surface finish of all granular layers on which bituminous works are to be placed, shall, unless
otherwise specifically instructed by the Engineer-in-Charge, be free from dust. All such layers must
be capable of being swept, after the removal of any non-integral loose material, by means of a
mechanical broom, without shedding significant quantities of material and dust removed by air jet,
washing, or other means approved by the Engineer-in-Charge.
B-10.1.5.2 Scarifying existing bituminous surface:
Where specified or shown on the drawings, the existing bituminous layer in the specified width
shall be removed with care and without causing undue disturbance to the underlying layer, by a
suitable method approved by the Engineer-in-Charge. After removal of all loose and disintegrated
material, the underlying layers which might have been disturbed should be suitably reworked and
compacted to line and level. After supplementing the base material as necessary with suitable fresh
stone, the compacted finished surface shall be primed with bitumen emulsion.

B-10.1.5.3 Patching of potholes and sealing of cracks

Where the existing surface to be overlaid is bituminous, existing potholes and cracks shall be
repaired and sealed following the conventional methods or as directed by the Engineer-in-Charge.
B-10.1.5.4 Laying the Profile Corrective Course
(a) Laying on existing bituminous surface: The existing bituminous surface shall be prepared in
accordance with Clause B-10.1.5.3, and after applying a tack coat. The bituminous profile
corrective course shall be laid and compacted to the requirements of the particular
specification.
(b) Correction of local depressions: Where local sags or depressions occur in the existing
pavement, a specific filling operation shall be instructed by the Engineer-in-Charge. Normally
the maximum layer of thickness at any point should not exceed 100 mm.

B-10.1.6 Surface finish and Quality control of work

Relevant provision of Clause B-9.2 and B-9.3 should be exercised.

B-10.1.7 Arrangement for traffic

During the above operation the flow of traffic shall be maintained to Clause B-9.1

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B-10.1.8 Measurement for Payment
The profile corrective course shall be measured as the volume instructed and compacted in position
and measured in cubic meters. The volume shall be calculated by plotting the exact profile of
profile corrective course as required, and laid, superimposed on the existing pavement profile.
Cross sectional areas of the profile corrective course shall be measured at intervals as used in the
design, or as determined by the Engineer-in-Charge.

B-10.2 PRIMER COAT OVER GRANULAR BASE

B-10.2.1 Scope:
This work shall consist of application of single coat of low viscosity liquid bituminous material to a
porous granular surface preparatory to any superimposition of bituminous treatment or mix.
B-10.2.2 Materials:
The choice of a bituminous primer shall depend upon the porosity characteristics of the surface to
be primed as classified in IRC: 16. These are:
(a) Surfaces of low porosity: such as wet mix macadam and water bound macadam.
(b) Surfaces of medium porosity: such as cement stabilized soil base.
(c) Surfaces of high porosity: such as a gravel base.
The different ranges of viscosity requirements for the primers to be used for the different types of
surfaces to be primed, as classified are given in Table B 10.2-1.
Table B 10.2-1: VISCOSITY REQUIREMENT AND QUANTITY OF BITUMINOUS PRIMER
Kinematic Viscosity Quantity of liquid bituminous
Type of surface
of Primer at 60ºC (Centistokes) material (kg) per 10 m2
Low porosity 30-60 6 to 9
Medium porosity 70-140 9 to 12
High porosity 250-500 12 to 15

B-10.2.3 Weather and Seasonal Limitations

The bituminous primer shall not be applied on a wet surface or during dust storm or when the
weather is foggy, rainy or windy. The prime coat for surface treatment should not be applied when
the temperature in the shade is less than 10ºC. Surfaces which are to receive emulsion primer
should be damp; but no free or standing water shall be present.

B-10.2.4 Construction:
(A) Equipment
The primer distributor shall be pneumatic tyred self-propelled pressure distributor equipped for
spraying the material uniformly at the specified rates and temperatures. Spraying by manual
methods may be allowed for small areas at the discretion of the Engineer. Power broom and/or
blowers may be supplemented by hand brooms as directed by the Engineer-in-Charge.
(B) Preparation of road surface
The surface to be primed shall be swept clean, free from dust and shall be dry. It shall be shaped to
the specified grades and section. It shall also be free from ruts, any other irregularities and

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segregated materials. Minor depression and potholes may be ignored until the surface is primed,
after which they shall be patched with a suitable premix material prior to the surface treatment.

(C) Application of bituminous primer

The viscosity and rate of application of the primer shall be specified in the Contract, or as
determined by site trials carried out as directed by the Engineer-in-Charge. The bituminous primer
shall be sprayed/ distributed uniformly over the surface. The method of application of the primer
will depend on the type of equipment to be used, size of nozzles, pressure at the spray bar and
speed of forward movement. The Contractor shall demonstrate at a spraying trial, that the
equipment and method to be used is capable of producing a uniform spray, within the tolerances
specified.

(D) Curing of primer and opening to traffic

It shall always be ensured that while opening to any kind of traffic, the primed surface is fully cured
and is not sticky to avoid being picked up by traffic. Normally, the primed surface shall be allowed
to cure for not less than 24 hours and during this period no traffic of any kind shall be permitted. A
very thin layer of sand may be applied to the surface of the primer, to prevent the primer from
being picked up by the wheels of the paver and the trucks delivering the bituminous materials to the
paver.

B-10.2.5 Quality Control of Work

Control on the quality of materials and work shall be exercised by the Engineer in accordance with
Clause B- 9.3.5.

B-10.2.6 Arrangement for Traffic

During the construction operations, arrangement of traffic shall be done as per Clause B-9.1.

B-10.3 TACK COAT

B-10.3.1 Scope
This work shall consist of application of a single coat of low viscosity liquid bituminous material to
an existing road surface preparatory to another bituminous construction over it when specified in
the Contract or instructed by the Engineer-in-Charge.
B-10.3.2 Materials
The binder used for tack coat shall be bituminous emulsion complying with IS: 8887 of a type and
grade as specified in the Contract or as directed by the Engineer-in-Charge. The use of cutback
bitumen as per IS: 217 shall be restricted only for sites as emergency applications as directed by the
Engineer-in-Charge.
B-10.3.3 Construction operation
(A) Equipment:
The tack coat distributor shall be a self-propelled or towed bitumen pressure sprayer, equipped for
spraying the material uniformly at a specified rate. Hand spraying of small areas, inaccessible to the
distributor, or in narrow strips, shall be sprayed with a pressure hand sprayer, or as directed by the
Engineer-in-Charge.

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(B) Preparation of base:
The surface on which the tack coat is to be applied shall be clean and free from dust, dirt, and any
extraneous material, and be otherwise prepared The surface on which the tack coat is to be applied
shall be clean and free from dust, dirt and any other extraneous material.
(C) Application of tack coat:
The application of tack coat shall be at rate specified in the Contract, and shall be applied
uniformly. If the rate of application of tack coat is not specified in the Contract then it shall be at
the rate specified in Table B 10.3-1. The normal range of spraying temperature for a bituminous
emulsion shall be 20ºC-70º C. For cutback bitumen of grade RC-70/MC-70, the temperature range
shall be 50ºC-80ºC. The method of application of the tack coat will depend on the type of
equipment to be used, size of nozzles, pressure at the spray-bar, and speed of forward movement.
The Contractor shall demonstrate at a spraying trial, that the equipment and method to be used is
capable of producing a uniform spray, within the tolerances specified.
Where the material to receive an overlay is a freshly laid bituminous layer, which has been
subjected to traffic, or contaminated by dust, a tack coat is not mandatory where the overlay is
completed within two days.
B-10.3.4 Curing of tack coat
The tack coat shall be left to cure until all the volatiles have evaporated before any subsequent
construction is started. No plant or vehicles shall be allowed on the tack coat other than those
essential for the construction.
B-10.3.5 Quality control of work
Control on the quality of materials and work shall be exercised by the Engineer-in-Charge in
accordance with Clause B-9.2 and Clause B-9.3.
Table B 10.3-1:RATE OF APPLICATION OF TACK COAT

Quantity of liquid bituminous material in kg per sq. meter

Type of Surface
area
Normal bituminous surfaces 0.20 to 0.25

Dry and hungry bituminous surfaces 0.25 to 0.30

Granular surfaces treated with primer 0.25 to 0.30

Non bituminous surfaces
(a) Granular base (not primed) 0.35 to 0.40
(b) Cement concrete pavement 0.30 to 0.35

B-10.3.6 Arrangement of traffic

During the period of construction the flow of traffic shall be maintained as per Clause B-9.1

B-10.3.7 Measurement for payment

Tack coat shall be measured in terms of surface area of application in sq. meter.

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B-10.4 BITUMINOUS MACADAM

B-10.4.1 Description
This work shall consist of construction, in a single course, of 50 mm to 100 mm. thickness or
multiple courses of compacted crushed aggregates premixed with a bituminous binder, laid
immediately after mixing, on a base prepared previously in accordance with the requirements of the
specifications, and in conformity with the lines, grades and cross-sections shown on the drawings
or directed by the Engineer-in-Charge.

B-10.4.2 Binder Materials

The bitumen shall be paving bitumen of suitable penetration grade within the range S 35 to S 90 or
A 35 to A 90 (30/40 to 80/100) as per Indian Standards Specification for “Paving Bitumen” IS:73.
The actual grade of bitumen to be used shall be decided by the Engineer-in-Charge appropriate to
the region, traffic, rainfall and other environmental conditions.

B-10.4.3 Aggregates

(A) Coarse Aggregates

The aggregates shall consist of crushed stone, crushed gravel (shingle) or other stones retained on
2.36 mm sieve. They shall be clean, strong, durable of fairly cubical shape and free of disintegrated
piece, organic and other deleterious matter, and adherent coatings. The aggregates shall preferably
be hydrophobic and of low porosity. Where crushed gravel is used as aggregates, not less than 90%
by weight of crushed materials retained on 4.75 mm sieve shall have at least two fractured faces.
The aggregates shall satisfy the physical requirements set forth in Table B 10.4-1.
Table B 10.4-1: PHYSICAL REQUIREMENTS FOR COARSE AGGREGATES FOR
BITUMINOUS MACADAM
Property Test Specification
Cleanliness Grain size analysis Max 5% passing 0.075 mm sieve

Particle shape Flakiness & Elongation Index Max 30%

(combined)

Strength Los Angeles Abrasion Value Max 40%

Aggregate Impact Value Max 30%

Durability Soundness
Sodium sulphate Max 12%
Magnesium sulphate Max 18%

Water absorption Water absorption Max 2%

Stripping Coating & Stripping of Bitumen Minimum retained coating 95%

Aggregates Mixtures

Water Sensitivity Retained Tensile Strength Min 80%

(B) Fine Aggregates:

Fine aggregates shall consists of crushed or naturally occurring material, or a combination of the
two, passing 2.36 mm sieve and retained on 75 micron sieve. They shall be clean, hard, durable, dry
and free from dust, and soft or friable matter, organic or other deleterious matter.

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B-10.4.4 Aggregate grading & binder content
When tested in accordance with IS: 2386 Part 1 (wet sieving method), the combined aggregate
grading for the particular mixture shall fall within the limits shown in Table B 10.4-2 for the
grading specified in the Contract. The type and quantity of bitumen, and appropriate thickness, are
also indicated for each mixture type.

B-10.4.5 Proportioning of materials

The aggregates shall be proportioned and blended to produce a uniform mixture complying with the
requirements of Table B 10.4-2. The binder content shall be within a tolerance of ± 0.3 % by
weight of total mixture when individual specimens are taken for quality control tests in accordance
with the provisions of Clause B- 9.3.4. The quantities of aggregates to be used shall be sufficient to
yield the specified thickness after compaction.

B-10.4.6 Construction Operations

(A) Weather and seasonal limitations
The work of laying Bituminous Macadam shall not be taken up during rainy or foggy weather or
when the base course is damp or wet or during dust storm or when the atmospheric temperature in
shade is 10ºC or less.
(B) Preparation of base
The base on which bituminous macadam is to be laid shall be prepared, shaped and compacted to
the specified profile in accordance with Clause B-10.1. A prime coat where needed shall be applied
as per relevant IRC-Specification.

Table B 10.4-2: COMPOSITION OF BITUMINOUS MACADAM

Mix designation Grading 1 Grading 2
Nominal aggregate size 40 mm 19 mm
Layer thickness 80 – 100 mm 50 – 75 mm
I.S. Sieve (mm) Cumulative % by weight of total aggregate passing
45 100 -
37.5 90-100 -
26.5 75-100 100
19 - 90-100
13.2 35-61 56-88
4.75 13-22 16-36
2.36 4-19 4-19
0.3 2-10 2-10
0.075 0-8 0-8
Bitumen content, % by
3.1 - 3.4 3.3 - 3.5
weight of total mixture
Bitumen Grade 35 to 90 35 to 90

(C) Tack coat

A tack coat as per Clause B-10.3 shall be applied as required by the Contract documents, or as
directed by the Engineer-in-Charge.

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(D) Preparation and transport of mix

Bituminous Macadam Mix shall be prepared in a Hot Mix Plant of adequate capacity and capable
to yield a mix of proper and uniform quality with thoroughly coated aggregates. Hot Mix Plant
shall be of suitable capacity, preferably of batch mix type. Total system for crushing of stone
aggregates and feeding of aggregate fractions in required proportions to achieve the desired mix,
deployed by the Contractor must be capable of meeting the overall specifications requirements
under stringent quality control. The plant shall have the following essential features:
(i) General
(a) The plant shall have coordinated set of essential units capable of producing uniform mix as per the
job mix formula.
(b) Cold aggregate feed system with minimum 4 bins having belt conveyor arrangement for initial
proportioning of aggregates from each bin in the required quantities. In order to have free flow of
fines from the bin, it is advisable to have vibrator fitted on bin to intermittently shake it.
(c) Belt conveyors below each bin should have variable speed drive motors. There should be
electronic load sensor on the main conveyor for measuring the flow of aggregates.
(d) Dryer unit with burner capable of heating the aggregate to the required temperature without any
visible un-burnt fuel or carbon residue on the aggregate and reducing the moisture content of the
aggregate to the specified minimum.
(e) The plant shall be fitted with suitable type of thermometric instruments at appropriate places so as
to indicate or record/register the temperature of heated aggregate, bitumen and mix.
(f) Bitumen supply unit capable of heating, measuring/metering and spraying of bitumen at specified
temperature with automatic synchronization of bitumen and aggregate feed in the required
proportion.
(g) A filler system suitable to receive bagged or bulk supply of filler material and its incorporation to
the mix in the correct quantity wherever required.
(h) A suitable built-in dust control system for the dryer to contain/recycle permissible fines into the
mix. It should be capable of preventing the exhaust of fine dust into atmosphere for environmental
control wherever so specified by the Engineer-in-Charge.
(i) The plant should have centralized control panel/cabin capable of presetting,
controlling/synchronizing all operations starting from feeding of cold aggregates to the discharge
of the hot mix to ensure proper quality of mix. It should have indicators for any malfunctioning in
the operation. Print out of the details of hot mix and all operations as stated above in each day shall
be available as and when required.
(j) Every hot mix plant should be equipped with siren or horn so that the operator may use the same
before starting the plant every time in the interest of safety of staff.
(ii) For Batch Type Plant
(a) Gradation control unit having minimum four deck vibratory screens for accurate sizing of hot
aggregate and storing them in separate bins. This unit should be fully covered to reduce the
maintenance cost and for better environmental condition.
(b) Proper arrangement for accurate weighing of each size of hot aggregate form the control panel
before mixing.
(c) Paddle mixer unit shall be capable of producing a homogeneous mix with uniform coating of all
particles of the mineral aggregate with binder.
(iii) For Continuous Type Plant
(a) Gradation control unit having vibratory screens for accurate sizing of hot aggregate and storing
them in separate bins. This unit should be fully covered to d\reduce the maintenance cost and for
better environmental condition.
(b) There should be appropriate arrangement for regulating and volumetric control of the flow of hot
aggregate form each bin to achieve the required proportioning.

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(c) Paddle mixer unit shall be capable of producing a homogeneous mix with uniform coating of all
particles of the mineral aggregate with binder.
(iv) For Drum Mix Plant
(a) It is a prerequisite that only properly screened and graded materials are fed to the bins. If required,
a vibratory screening unit shall be installed at the plant site to ensure the same.
(b) Belt conveyors below each bin should have variable speed drive motors. There should be
electronic load sensor on the main conveyor for measuring the flow of aggregate.
(c) There should be arrangement to measure moisture content of the aggregate (s) so that moisture
correction may be applied for working out requirements of binder and filler.
(d) The temperature of binder at the time of mixing and that of the aggregate shall provided that the
difference in temperature between the binder and aggregate at no time exceeds 14ºC.
(e) Mixing shall be thorough to ensure that a homogeneous mixture is obtained in which all particles
of the aggregates are coated uniformly, and the discharge temperature of mix shall be between
130ºC to 160ºC.
(f) The mixture shall be transported from the mixing plant to the point of use in suitable tipper
vehicles. The vehicles employed for transport shall be clean and be covered in transit if so directed
by the Engineer-in-Charge. Any tipper causing excessive segregation of materials by its spring
suspension or other contributing factors or that which show as undue delay shall be removed from
the work until such conditions are corrected.
(E) Spreading
The mix transferred from the tipper at work site to the pave shall be spread immediately by means
of a self propelled mechanical paver with suitable screeds capable of spreading, tamping and
finishing the mixture to the specified lines, grade and cross-sections.
The paver finisher shall have the following essential features:
(a) Loading hoppers and suitable distributing mechanism.
(b) All drives having hydrostatic drive / control.
(c) The machine shall have a hydraulically extendable screed for appropriate width requirement.
(d) The screed shall have tamping and vibrating arrangement for initial compaction to the layer as it is
spread without rutting or otherwise marring the surface. It shall have adjustable amplitude and
variable frequency.
(e) The paver shall be equipped with necessary control mechanism so as to ensure that the finished
surface is free from surface blemishes.
(f) The paver shall be fitted with an electronic sensing device for automatic leveling and profile
control within the specified tolerances.
(g) The screed shall have the internal heating arrangement.
(h) The paver shall be capable of laying either 2.5 to 4.0 m width or 4.0 to 7.0m width as stipulated in
the Contract.
(i) The paver shall be so designed as to eliminate skidding / slippage of the tyres during operation.
However, in restricted locations and in narrow widths, where the available plants can not operate in
the opinion of the Engineer-in-Charge he may permit manual laying of the mix.
The temperature of mix at the time of laying shall be in the range 120ºC to 135ºC.
In multilayer construction, the longitudinal joint in one layer shall off set that in the layer below by
about 150 mm. However, the joint in the topmost layer shall be at the centre line of the pavement.
Longitudinal joints and edges shall be constructed true to the delineating line parallel to the centre
line of the road. All joints shall be cut vertical to the full thickness of the previously laid mix and
the surface painted with hot bitumen before placing fresh material.

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(F) Rolling
After the spreading of mix, rolling shall be done by 8 to 10 tonne power rollers or other approved
plant. Rolling should start as soon as possible after the material has been spread. Rolling shall be
done with care to keep from unduly roughening the pavement surface. Rolling of the longitudinal
joint shall be done immediately behind the paving operation. After this the rolling shall commence
at the edges and progress towards the centre longitudinally except that on super elevated portions it
shall progress from the lower to the upper edge parallel to the centre line of the pavement.
The initial of break-down rolling shall be done with 8-10 tonne static weight smooth wheel roller (3
wheels or tandem), as soon as it is possible to roll the mix without cracking the surface or having
the mix pick up on the roller wheels. The second or intermediate rolling shall follow the break-
down rolling with vibratory roller of 8-10 tonne static weight or pneumatic tyred roller 15-25 tonne
weight, with minimum 7 wheels and minimum tyre pressure of 0.7 MPa as closely as possible to
the paver and be done while the paving mix is still at a temperature that will result in maximum
density. The final rolling shall be done while material is still workable enough for removal of roller
marks, with 6-8 tonne tandem roller. During the final rolling, vibratory system shall be switched
off. The joints and edges shall be rolled with 8-10 tonne static roller.
When the roller has passed over the whole area once, any high spots or depressions which become
apparent shall be corrected by removing or adding mix material. The rolling shall then be continued
till the entire surface has been rolled properly and as per the direction of Engineer-in-Charge, so
that, there is no crushing of aggregates and all roller marks have been eliminated. Each pass of the
roller shall uniformly overlap not less than one-third of the track made in the preceding pass. The
roller wheel shall be kept damp if necessary to avoid bituminous material from sticking to the
wheels and being picked up. In no case fuel, lubricating oil shall be used for this purpose.
Excessive pouring of water on the wheels should be avoided.
All manufacturing & rolling temperatures of mix shall conform to Table B 10.7-7.
Rollers shall not stand on newly laid material while there is a risk that it will be deformed thereby.
The edges along & transverse of the bituminous macadam laid and compacted earlier shall be cut to
their full depths so as to expose fresh surface which shall be painted with a thin surface coat of
appropriate binder before the new mix is placed against it.

B-10.4.7 Surface Finish and Quality Control of Work

The surface finish of the completed construction shall conform to the requirement of Clause B-
9.2.1. For control on the quality of materials and the works carried out, the relevant provisions of
quality control of road works shall apply.

B-10.4.8 Protection of the Layer

The bituminous macadam shall be covered with either the next pavement course or wearing course,
as the case may be within a maximum of forty-eight hours. If there is to be any delay, the course
shall be covered by a seal coat before allowing any traffic over it.

B-10.4.9 Arrangements for Traffic :

The provision of Clause B-9.1 shall apply as regards the flow or traffic during construction.

B-10.4.10 Measurement for Payment :

Bituminous Macadam work shall be measured as finished work in square meters.

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B-10.5 BITUMINOUS PENETRATION MACADAM
B-10.5.1 Description
The work shall consist of the construction of one or more layers of compacted crushed coarse
aggregates with alternate applications of bituminous binder and key aggregates in accordance with
the requirements of these specifications to serve as base course and in conformity with the lines,
grades and cross-sections shown on the drawing as directed by the Engineer-in-Charge. Thickness
of an individual course shall be 50 mm or 75 mm, or as specified.
B-10.5.2 Materials
(a) Binder
The binder shall be of a suitable grade such as straight run bitumen 80/100, 60/70, 30/40, as
directed by the Engineer-in-Charge, satisfying the requirements of IS: 73, 217 or 454. The actual
grade of bitumen, tar or cut back to be used shall be decided by the Engineer-in-Charge appropriate
to the region, traffic and other environmental condition.
(b) Aggregates
The aggregate shall consist of crushed stone, crushed gravel (shingle) or other hard materials as
specified by the Engineer-in-Charge and shall retain on 2.36 mm sieve. They shall be clean, strong,
durable, fairly cubical shape and free from disintegrated pieces, salt, alkali, vegetable matter, dust
or other deleterious matter and adherent coatings.
The aggregates shall preferably be hydrophobic and of low porosity. Before approval of the source,
the aggregates shall be tested for stripping.
The course and key aggregates shall conform to the grading given in Table B 10.5-1.
B-10.5.3 Quantities of Materials
The quantities of material used for this work shall be as specified in Table B 10.5-1.
B-10.5.4 Construction Operations
(a) Weather and Seasonal limitations
The provisions of Clause 10.4.6 shall apply.
(b) Preparation of base
The underlying course on which the Penetration Macadam Course is to be laid shall be prepared,
shaped and conditioned to the specified lines, grades and sections as per Clause B-10.1 or as
directed by the Engineer-in-Charge. A prime coat, where specified, may be applied in accordance
with the I.R.C’s specification for priming of base course with bituminous primers. A tack coat as
per Clause B-10.3 shall be applied.
(c) Spreading and Compacting Coarse Aggregates
The coarse aggregate in dry and clean form, shall be spread uniformly and evenly at the rate
specified in Table B 10.5-1. The surface of the layer shall be carefully checked with camber
templates to ensure correct line and level and cross fall. All high and low spots remedied by
removing or adding aggregates, as may be required.
The spreading shall be carried no further in advance of the rolling and penetrating operations that
can be completed in one average day’s work. Segregated aggregates or aggregates mixed with earth
or other foreign substance shall be removed and replaced with graded aggregates.

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Table B 10.5-1: Composition of Bituminous Penetration Macadam

I.S. Sieve Cumulative per cent by weight of total aggregate passing
Designation For 50 mm. compacted thickness For 75 mm. compacted thickness
(mm) Coarse Aggregate Key Aggregate Coarse Aggregate Key Aggregate
63 - - 100 -

45 100 - 58-82 -

26.5 37-72 - - 100

22.4 - 100 5-27 50-75

13.2 2-20 50-75 - -

11.2 - - - 5-25

5.6 - 5-25 - -

2.8 0-5 0-5 0-5 0-5

Approx. loose
aggregate
0.06 0.015 0.09 0.018
quantities
(cu.m / sq.m.)
Binder quantity
(kg/m2) 5.0 6.8

(d) Compaction
After the spreading of coarse aggregates dry rolling shall be done by 8-10 tonne smooth wheeled
steel roller. Rolling shall start as soon as possible after the material has been spread. The rolling
shall commence at the edges, overlapping the shoulder at least 30 cm and progress towards the
centre longitudinally except on super elevated portions where it shall progress from the lower to the
upper edge after the edges have been rolled. For super elevated portions, the overlapping should be
approximately one third of the width of the rear wheel on each trip.
After the initial dry rolling, the surface shall be checked with a crown template and a 3 meter
straight edge. The surface shall not vary more than 10 mm from the template or straight-edge. All
surface irregularities exceeding the above limit shall be corrected by removing or adding aggregates
as required.
The rolling shall be done until the compacted coarse aggregate has a firm surface true to the cross-
section shown on the plans and has a texture that will allow free and uniform penetration of the
bituminous materials.
(e) Application of bituminous material
After the coarse aggregate has been rolled and checked, the bituminous binder shall be applied at
specified temperature directed by the Engineer-in-Charge. The rate of application shall be as
specified in Table B 10.5-1. At the time of applying the binder, the aggregates shall be surface dry
for the full depth of the layer.
The bituminous material shall preferably be applied by a pressure distributor uniformly over the
surface at the specified rate. Over small areas, where the use of a spray bar is impracticable, the
material shall be applied by the nozzle attachment. Only when permitted, pouring pots may be used
according to the directions of the Engineer-in-Charge.

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(f) Application of key aggregates
Immediately after the first penetration of bitumen, the key aggregates in a clean and dry state shall
be spread uniformly over the surface by means of an approved mechanical spreader or by approved
manual methods at the rate specified in Table above.
If necessary, the surface shall be broomed to ensure uniform application of the key aggregates. The
entire surface shall then the rolled with 8-10 tons smooth steel wheel roller (or vibratory roller
operating in non-vibratory mode).
B-10.5.5 Surface Finish and Quality Control
The surface finish of construction shall conform to the requirements of Clause B-9.2.1. Controls on
the quality of materials and works shall be exercised as per, the relevant provisions of quality
control of road works shall apply.
B-10.5.6 Arrangements for Traffic
During the period of construction, arrangements for traffic shall be made as per Clause B-9.1.
B-10.5.7 Opening to traffic
The Penetration macadam shall be provided with a surfacing without any delay. If there be any
delay, the course shall be covered by a seal coat to the requirements of relevant clause before
allowing any traffic over it.
B-10.5.8 Measurements for payment
Penetration Macadam Base / Binder Course shall be measured as finished work in square meters.

B-10.6 BUILT-UP SPRAY GROUT

B-10.6.1 Description
This work shall consist of a two-layer composite construction of compacted crushed coarse
aggregates with application of bituminous binder after each layer, and key aggregates on the top of
the second layer, in accordance with requirements of these specifications to serve as a base course
and in conformity with lines, grades and cross-sections shown on the drawings or as directed by the
Engineer-in-Charge. Thickness of the course shall be 75 mm.
B-10.6.2 Materials
(a) Binder
The binder shall be straight run bitumen of a suitable grade, as directed by the Engineer-in-Charge.
(b) Aggregates
The aggregates shall consist of crushed stone, crushed gravel (shingle) or other stones. They shall
be clean, strong, durable, of fairly cubical shape and free of disintegrated pieces, organic or other
deleterious matter and adherent coatings. The aggregates shall preferably be hydrophobic and of
low porosity.
The aggregates shall satisfy the physical requirements set forth in Table B 10.4-1. The coarse and
key aggregates for built-up spray grout shall conform to the grading given in Table B 10.6-1.

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Table: B 10.6-1: GRADING REQUIREMENT OF COARSE AND KEY AGGREGATES FOR

BUILT-UP SPRAY GROUT
I.S. Sieve Designation Cumulative percent by weight of total aggregate passing
(mm) Coarse Aggregate Key Aggregate
53.0 100 -
26.5 40-75 -
22.4 - 100
13.2 0-20 40-75
5.6 - 0-20
2.8 0-5 0-5

B-10.6.3 Construction Operations

(a) Weather and seasonal limitation

Built up spray-grout shall not be constructed during rainy or foggy weather or when the base is
damp or wet or during dust storm or when the atmospheric temperature in shade is 10ºC or below.

(b) Preparation of base

The base on which built up spray grout is to be constructed shall be prepared, shaped and
compacted to the specified lines, grades and cross-sections in accordance with Clause B-10.1 as
directed by the Engineer-in-Charge. The surface shall be thoroughly swept and scraped clean of
dust and other foreign matter. A priming coat shall be applied with approved primer as per relevant
IRC-Clause.

(c) Tack Coat

A tack coat complying with specifications for tack coat mentioned under Clause B-10.3 shall be
applied over the base preparatory to the construction of spray grout course.

(d) Spreading and rolling coarse aggregates for the first layer
Immediately after the application of tack coat, the coarse aggregates in a dry and clean form shall
be spread uniformly and evenly at the rate of 0.5 m3 per 10 m2 area.
Immediately after spreading of the aggregates, the entire surface shall be rolled with a 8-10 tonne
smooth wheeled steel roller. Rolling shall commerce at the edges and progress towards the centre
except in super elevated portions where it shall proceed from the inner edge to the outer. Each pass
of the roller shall uniformly overlap not less than one-third of the track made in the preceding pass.
The surface of the layer shall be carefully checked with templates and all high and low spots
remedied by removing or adding aggregate as may be required.
After initial rolling the surface shall be checked transversely and longitudinally with templates and
any irregularities corrected by loosening the surface, adding or removing necessary amounts of
aggregate, followed by rolling.

(e) Application of binder - first spray

The binder shall be heated to the temperature appropriate to grade of bitumen approved by the
Engineer-in-Charge and sprayed on aggregate layer at the rate of 15 Kg./10m2 in a uniform manner
with the help of mechanical sprayers. Excessive deposits of binder caused by stopping or starting of
the sprayers or through leakage or for any other reason shall be removed and made good.

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(f) Spreading and rolling of coarse aggregate for the second layer
Immediately after the first application of binder, the second layer of coarse aggregates shall be
spread and rolled as in the case of coarse aggregates for the first layer.

(g) Application of binder-second spray

The second aggregate layer shall then be given a binder spray at the rate of 15 Kg./10m2 as for the
case of application of binder-first spray, mentioned above in (e).

(h) Application of key aggregate

Immediately after application of the binder, key aggregates in a clean and dry state shall be spread
uniformly at the rate of 0.13m3/10m2 so as cover the surface completely. If necessary, the surface
shall be broomed to ensure uniform application of the key aggregates. The entire surface shall then
be rolled with a 8-10 tonne smooth wheeled roller in the manner as stated in para (d) above. While
rolling is in progress additional key aggregates, where required, shall be spread by hand. Rolling
shall continue until the entire course is thoroughly compacted and the key aggregates are firmly in
position.
B-10.6.4 Surface Finish and Quality Control
The surface finish of construction shall conform to the requirements of Clause B-9.2.
Control on the quality of materials and works shall be exercised by the Engineer-in-Charge in
accordance with Clause B-9.3.
B-10.6.5 Arrangement for Traffic
The provisions of Clause B-9.1 shall apply as regards the flow of traffic during construction.
B-10.6.6 Measurement for payment
Built-up spray grout shall be measured as finished work in square meters.

B-10.7 DENSE BITUMINOUS MACADAM

B-10.7.1 Scope
The work shall consist of construction in a single course of 50 to 100 mm. thick base/binder course
to the following specifications on a previously prepared base.
B-10.7.2 Materials
(a) Binder
Clause B-10.6.2, Sub-paragraph (a) shall apply.
(b) Coarse aggregates
The coarse aggregates shall consist of crushed rock, crushed gravel or other hard materials retained
on 2.36 mm sieve. They shall be clean, hard, and durable, of cubical shape, free from dust and soft
or friable matter, organic or other deleterious matter. Where the Contractor’s selected source of
aggregates have poor affinity for bitumen, as a condition for the approval of that source, the
bitumen shall be treated with an approved anti-stripping agent, as per the manufacturer’s
recommendations, without additional payment. Before approval of the source, the aggregates shall
be tested for stripping. The aggregates shall satisfy the physical requirements specified in Table B
10.7-1, for dense bituminous macadam.

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Table B 10.7-1: PHYSICAL REQUIREMENT FOR COARSE AGGREGATES FOR DENSE

BITUMINOUS MACADAM
Property Test Specification
Cleanliness (dust) Grain size analysis Max 5% passing 0.075 mm sieve

Particle shape Flakiness & Elongation Index (combined) Max 30%

Strength* Los Angeles Abrasion Value Max 35%

Aggregate Impact Value Max 27%

Durability Soundness
Sodium Sulphate Max 12%
Magnesium Sulphate Max 18%

Water Absorption Water absorption Max 2%

Stripping Coating & Stripping of Bitumen Minimum retained coating 95%

Aggregate Mixtures

Water Retained Tensile Strength Min 80%

Sensitivity**
* Aggregates may satisfy requirements of either of the two tests.
** The water sensitivity test is only required, if the minimum retained coating in the stripping test is less than 95%.
Where crushed gravel is proposed for use as aggregate, not less than 90% by weight of the crushed
material retained on the 4.75 mm sieve shall have at least two fractured faces.
(c) Fine aggregates
Fine aggregates shall be crushed or naturally occurring material, or a combination of the two,
passing 2.36 mm sieve and retained on 75 micron sieve. They shall be clean, hard, durable,
uncoated, dry and free from dust and soft or friable matter, organic or other deleterious substances.
The fine aggregates shall have a sand equivalent value of not less than 50 when tested in
accordance with the requirement of IS: 2720 (Part 37).
The plasticity index of the fraction passing the 0.425 mm sieve shall not exceed 4, when tested in
accordance with IS : 2720 (Part 5).
(d) Filler :
The filler shall consist of finely divided mineral matter such as rock dust, hydrated lime or cement
as approved by the Engineer-in-Charge. The filler shall be graded within the limits indicated in
Table B 10.7-2.

Table B 10.7-2: GRADING REQUIREMENT FOR MINERAL FILLER

Cumulative percent passing
IS Sieve (mm)
by weight of total aggregate
0.60 100
0.30 95-100
0.075 85-100
The filler shall be free from organic impurities and have a Plasticity Index not greater than 4. The
Plasticity Index requirement shall not apply if filler is cement or lime. When the coarse aggregate is
gravel, 2% by weight of total aggregate, shall be Portland cement or hydrated lime and the
percentage of fine aggregate reduced accordingly. Cement or hydrated lime is not required when
the limestone aggregate is used. Where the aggregates fail to meet the requirements of the water
sensitivity test in Table above, then 2% by total weight of aggregate, of hydrated lime shall be
added without additional cost.
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B-10.7.3 Aggregate grading and Binder content
The combined grading of the coarse and fine aggregates and added filler for the particular mixture
shall fall within the limits shown in Table B 10.7-3 for dense bituminous macadam grading 1 or 2
as specified in the Contract. The type and quantity of bitumen, and appropriate thickness, are also
indicated for each mixture type.
TABLE B 10.7-3: COMPOSITION OF DENSE BITUMINOUS MACADAM
Grading 1 2
Nominal aggregate size 40 mm 25 mm
Layer Thickness 80 - 100 mm 50 - 75 mm
1
IS Sieve (mm) Cumulative % by weight of total aggregate passing
45 100 --
37.5 95-100 100
26.5 63-93 90-100
19 -- 71-95
13.2 55-75 56-80
9.5 -- --
4.75 38-54 38-54
2.36 28-42 28-42
1.18 -- --
0.6 -- --
0.3 7-21 7-21
0.15 -- --
0.075 2-8 2-8
Bitumen content % by
Min 4.0 Min 4.5
mass of total mix2
Bitumen Grade
65 or 90 65 or 90
(penetration)

TABLE B 10.7-4: REQUIREMENT OF DENSE BITUMINOUS MACADAM MIX

1. Minimum Stability (kN at 600 C) 9.0
2. Minimum flow (mm) 2
3. Maximum flow (mm) 4
4. Compaction level (Number of blows) 75 blows on each of the two faces of the specimen
5. Per cent air voids 3-6
6. Per cent voids in mineral aggregate (VMA) As per Table B 10.7-5
7. Per cent voids filled with bitumen (VFB) 65-75
Notes:
1. The combined aggregate grading shall not vary from the low limit on one sieve to the high limit on the adjacent
sieve.
2. Determined by the Marshall method.
B-10.7.4 Mix Design
(a) Requirement of mixture
Apart from conformity with grading and quality requirements for individual ingredients, the
mixture shall meet the requirements set out in Table B 10.7-4:
(b) Job mix formula
The Contractor shall intimate to the Engineer-in-Charge in writing, at least 20 days before the start
of the work, the job mix formula proposed to be use by him for the work and shall give the
following details:
(i) Source and location of all materials;

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(ii) Proportions of all materials expressed as follows where each is applicable:

(a) Binder, as percentage by weight of total mix.
(b) Coarse aggregate / Fine aggregate / Mineral filler as percentage by weight of total
aggregate including mineral filler.
(iii) A single definite percentage passing each sieve for the mixed aggregate.
(iv) The results of tests enumerated in Table B 10.7-4 as obtained by the Contractor.
(v) Test results of physical characteristics of aggregates to be used.
(vi) Mixing temperature and compacting temperature.
(vii) Where the mixer is a batch mixer, the individual weights of each type of aggregate, and binder
per batch.
While working out the job mix formula, the Contractor shall ensure that it is based on a correct and
truly representative sample of the materials that will actually be used in the work and that the
mixture and its different ingredients satisfy the physical and strength requirements of these
Specifications.
Approval of the job mix formula shall be based on independent testing by the Engineer-in-Charge
for which samples of all ingredients of the mix shall be furnished by the Contractor as required by
the former.
The approved job mix formula shall remain effective unless and until modified by the Engineer-in-
Charge. Should a change in the source of materials be proposed, a new job mix formula shall be
established and got approved from the Engineer-in-Charge before actually using the materials.
TABLE B 10.7-5: MINIMUM PERCENT VOIDS IN MINERAL AGGREGATE (VMA)
Nominal Maximum Minimum VMA, percent related in Design Air Voids2 (%)
Particle Size1
3.0 4.0 5.0
(mm)
9.5 14.0 15.0 16.0
12.5 13.0 14.0 15.0
19.0 12.0 13.0 14.0
25.0 11.0 12.0 13.0
37.5 10.0 11.0 12.0
1 - The nominal maximum particle size is one size larger than the first sieve to retain more than 10%.
2 - Interpolate minimum voids in the mineral aggregates (VMA) for designs air voids values between those listed.
(c) Permissible variation from job mix formula
It shall be the responsibility of the Contractor to produce a uniform mix conforming to the
approved job mix formula subject to the permissible variations of the individual percentage of the
various ingredients in the actual mix from the job mix formula to be used within the limits as
specified in the Table B 10.7-6. These variations are intended to apply to individual specimens
taken for quality control tests vide Section B-9.

Table B 10.7-6: PERMISSIBLE VARIATION FROM THE JOB MIX FORMULA

Permissible variation
Description
Base/binder course Wearing course
Aggregate passing 19 mm sieve or larger ± 8% ± 7%
Aggregate passing 13.2 mm, 9.5 mm ± 7% ± 6%
Aggregate passing 4.75 mm sieve ± 6% ± 5%
Aggregate passing 2.36 mm,1.18 mm,0.6 mm ± 5% ± 4%
Aggregate passing 0.3 mm,0.15 mm. ± 4% ± 3%
Aggregate passing 0.075mm sieve ± 2% ± 1.5%
Binder content ± 0.3% ± 0.3%
Mixing temperature ± 10º C ± 100 C

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Once the plant trials have demonstrated the capability of the plant, and the trials are approved, the
laying operation may commence. Over the period of the first month of production for laying of the
works, the Engineer-in-Charge shall require additional testing of the product to establish the
reliability and consistency of the plant.
(d) Laying Trials
Once the plant trials have been successfully completed and approved, the Contractor shall carry out
laying trials, to demonstrate that the proposed mix can be successfully laid, and compacted. The
laying trial shall be carried out on a suitable area which is not to form part of the works, unless
specifically approved in writing, by the Engineer-in-Charge. The area of the laying trials shall be a
minimum of 100 m2 of construction similar to that of the project road, and it shall be in all respects,
particularly compaction, the same as the project construction, on which the bituminous material is
to be laid.
The Contractor shall previously inform the Engineer-in-Charge of the proposed method for laying
and compacting the material. The plant trials shall then establish if the proposed laying plant,
compaction plant, and methodology is capable of producing satisfactory results. The density of the
finished paving layer shall be determined by taking cores, no sooner than 24 hours after laying, or
by other approved method.
B-10.7.5 Construction Operations
(a) Preparation of base
The base on which Dense Bituminous Macadam is to be laid shall be prepared, shaped and
conditioned to the specified lines, grades and cross sections as directed by the Engineer. The
surface shall be thoroughly swept clean free from dust and foreign matter using mechanical broom
and dust removed or blown off by compressed air. In portions where mechanical means cannot
reach, other approved method shall be used. Where the material on which the dense bituminous
macadam is to be laid is other than a bitumen bound layer, a prime coat shall be applied.
(b) Tack Coat
Where the material on which the dense bituminous macadam is to be placed is a bitumen bound
surface, a tack coat shall be applied.
(c) Equipments
For details of Hot Mix Plant, Paver etc. please refer details in Clause B-10.6 Bituminous Macadam.
(d) Spreading
The mix transported from the hot mix plant to the site shall be spread by means of a self-propelled
pave with suitable screeds capable of spreading, tamping and finishing the mix to specified grade,
lines and cross-section. In restricted locations and in narrow widths where the available equipment
cannot be operated in the opinion of the Engineer-in-Charge, he may permit manual laying of the
mix. Similarly for smaller jobs, mechanical paver may be used with the approval of the Engineer.
TABLE B 10.7-7: Manufacturing & Rolling Temperatures
Bitumen Penetration Bitumen Aggregate Mixed Rolling Laying
Mixing Mixing Material
(0C) (0C) (0C) (0C) (0C)
65 150-165 150-170 165 Max. 90 Min. 125 Min.
90 140-160 140-165 155 Max. 80 Min. 115 Min.

Appropriate mixing temperatures can be found in Table B 10.7-7; the difference in temperature
between the binder and aggregate should at no time exceed 140 C. In order to ensure uniform
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quality of the mix and better coating of the aggregates, the hot mix plant shall be calibrated from
time to time.
(e) Compaction
After spreading the mix by paver, it shall be thoroughly compacted by rolling with a set of rollers
moving at a speed not more than 5 Km/h, immediately following the paver.
Generally the initial or breakdown rolling shall be done with 8-10 tonne dead weight smooth-
wheeled roller. The intermediate rolling shall be done with 8-10 tonne dead weight or vibratory
roller or with a pneumatic tyred roller of 12-15 tonne weight having nine wheels with a tyre
pressure of at least 5.6 kg/cm2. The finish rolling shall be done with 6-8 tonne smooth wheeled
tandem rollers.
All the compaction operations i.e. breakdown rolling and intermediate rolling can be accomplished
by using vibratory tandem roller of 8-10 tonne static weight.
During initial breakdown rolling and finish rolling, no vibratory compaction shall be resorted to.
The exact pattern of rolling shall be established after as a result of reversing of the direction of a
roller of from any other cause shall be corrected at once as specified and / or removed and made
good. The rollers shall not be permitted to stand on pavement which has not been fully compacted
and where temperature is still more than 70º C. Necessary precautions shall be taken to pavement
either when the rollers are operating or standing.
The wheels of roller shall be kept moist to prevent the mix from adhering to them. But in no case
shall fuel / lubricating oil be used for this purpose nor did excessive water pour on the wheels.
Rolling shall commence longitudinally from edges and proceed towards the centre, except that on
super elevated and unidirectional cambered portions, it shall progress from the lower to upper edge
parallel to the centre line of the pavement.
The roller shall proceed on the fresh material with rear or fixed wheel leading so as to minimise the
pushing of the mix and each pass of the roller shall overlap the preceding one by half the width of
the rear wheel.
Rolling shall be continued until the specified density is achieved, or where no density is specified,
until there is no further movement under the roller. Skin patching of an area that has been rolled
will not be permitted. Rolling operations shall be completed in all respects before the temperature
of the mix falls below as specified in Table B 10.7-7.
B-10.7.6 Opening to Traffic
Traffic may be allowed at least 24 hours after completion of the final rolling.
B-10.7.7 Surface Finish and Quality Control of Work
The surface finish of the completed construction shall conform to the requirements of IRC Code.
Control on the quality of materials and works shall be exercised by the Engineer in accordance with
Clause B-9.2.
B-10.7.8 Arrangements for Traffic :
During the period of construction, arrangements for the traffic shall be done as per Clause B-9.1
and as per direction of Engineer-in-Charge.

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B-10.8 SEMI-DENSE BITUMINOUS CONCRETE
B-10.8.1 Description
This work shall consist of construction in single or multiple layers of semi-dense bituminous
concrete on a previously prepared bituminous base. A single layer shall be 25 mm to 40 mm in
thickness.
B-10.8.2 Materials
(a) Binder
The bitumen shall be paving bitumen of penetration grade complying with IS: 73 and of the
penetration indicated in Table B 10.8-2, or modified bitumen as specified in the Contract.
(b) Coarse aggregates
The coarse aggregates shall be generally as specified in Clause 10.7.2, except that the
aggregates shall satisfy the physical requirements of Table B 10.8-1.
Table B 10.8-1: PHYSICAL REQUIREMENT FOR COARSE AGGREGATES FOR SEMI -
DENSE BITUMINOUS CONCRETE
Property Test Specification
Cleanliness (dust) Grain size analysis Max 5% passing 0.075 mm
sieve

Particle shape Flakiness & Elongation Index Max 30%

(combined)

Strength* Los Angeles Abrasion Value Max 35%

Aggregate Impact Value Max 27%

Polishing Polished Stone Value Min 55

Durability Soundness
Sodium Sulphate Max 12%
Magnesium Sulphate Max 18%

Water Absorption Water absorption Max 2%

Stripping Coating & Stripping of Bitumen Minimum retained coating

Aggregate Mixtures 95%

Water sensitivity** Retained Tensile Strength Min 80%

(c) Fine aggregates

The fine aggregates shall be as specified in Clause 10.7.2.
(d) Filler
Filler shall be generally as specified in Clause 10.7.2. Where the aggregates fail to meet the
requirements of the water sensitivity test in Table B 10.8-1, 2% by total weight of aggregate
of hydrated lime shall be added without additional cost.
(e) Aggregate gradation
The mineral aggregate, including mineral filler, shall be so graded or combined so as to
conform to grading set forth in Table B 10.8-2.

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Table B 10.8-2: COMPOSITION OF SEMI-DENSE BITUMINOUS CONCRETE PAVEMENT

LAYERS
Grading 1 2
Nominal aggregate size 13 mm 10 mm
Layer Thickness 35-40 mm 25-30 mm
IS Sieve1 (mm) Cumulative % by weight of total aggregate passing
19 100 --
13.2 90-100 100
9.5 70-90 90-100
4.75 35-51 35-51
2.36 24-39 24-39
1.18 15-30 15-30
0.6 -- --
0.3 9-19 9-19
0.15 -- --
0.075 3-8 3-8
Bitumen content % by
Min. 4.5 Min. 5.0
mass of total mix2
Bitumen Grade (pen) 65* 65*
Notes: 1. The combined aggregate grading shall not vary from the low limit on one sieve
to the high limit on the adjacent sieve.
2. Determined by the Marshall method.
* only in exceptional circumstances, 80/100 penetration grade may be used, as approved by the Engineer-
in-Charge.

B-10.8.3 Mixture Design

(a) Requirement of mixture
Apart from conformity with the grading and quality requirements for indivual ingredients the
mixture shall meet the requirements set out in Table B 10.8-3.
Table B 10.8-3: REQUIREMENTS OF SEMI-DENSE BITUMINOUS CONCRETE PAVEMENT
LAYERS
Minimum stability (kN at 600 C) 8.2
Minimum flow (mm) 2
Maximum flow (mm) 4
Compaction level (Number of blows) 75 blows on each of the two faces of the specimen
Percent air voids
Percent voids in mineral aggregate (VMA) See Table B 10.7-5
Percent voids filled with bitumen (VFB) 65-78
The requirements for minimum per cent voids in mineral aggregates (VMA) are set out in Table B-
10.7-5. [Minimum Per Cent Voids in Mineral Aggregate (VMA)]
(b) Binder content
The binder content shall be optimized to achieve the requirements or the mixture set forth in Table
B 10.8-2 and the traffic volume as specified in the Contract. The Marshall method for determining
the optimum binder content shall be adopted.
B-10.8.4 Job mix formula
The procedure for formulating the job mix formula shall be generally specified in Clause B-10.7.4
and the results of tests enumerated in Table B 10.8-3 as obtained by the Contractor.

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B-10.8.5 Permissible variation from Job mix formula
The contractor shall have the responsibility of ensuring proper proportions of materials in
accordance with the approved job mix formula and producing a uniform mix. The permissible
variations of the individual percentage of the various ingredients in the actual mix from the job mix
formula may be within the limits as specified in Table under Clause B-10.7.6 (Permissible variation
from Job Mix Formula).
B-10.8.6 Construction operations
(a) Weather and seasonal limitations
Relevant guidelines for Bituminous Macadam, vide Clause B-10.4.6(A), shall apply.
(b) Preparation of base
The base on which semi-dense bituminous concrete is to be laid shall be prepared, shaped and
conditioned to the specified lines, grade and cross-sections as directed by the Engineer-in-Charge.
The surface shall be thoroughly swept and scrapped clean and free of dust and foreign matter.
(c) Tack coat
Where specified in the Contract, a tack coat complying with Clause B-10.3 shall be applied over
the base. Application of tack coat shall, however not be necessary when laying follows soon after
the provision of a bituminous base, without opening to traffic.
(d) Preparation of mix
Semi-Dense Bituminous Concrete Mix shall be prepared in a Hot Mix Plant of adequate capacity
and specification as laid down in Clause B 10.4.6 (D). The temperature of binder at the time of
mixing shall be in the range of 150ºC-177ºC and of aggregates in the range 155ºC-163ºC. At no
time the difference in temperature between the aggregates and the binder shall exceed 14ºC.
Mixing shall be thorough to ensure that a homogeneous mixture is obtained in which all the
particles of the mineral aggregates are coated uniformly. The mix shall be transported from the
mixing plant to the point of use in suitable vehicles. The vehicles employed for transport shall be
clean and the covered over in transit if so directed by the Engineer-in-Charge.
(e) Spreading
Refer specification as per Clause B 10.4.6 (E).
(f) Rolling
Refer specification as per Clause B 10.7.5 (e).
B-10.8.7 Opening to traffic
Traffic may be allowed immediately after completion of the final rolling when the mix has cooled
down to the surrounding temperature.
B-10.8.8 Surface finish & quality control of work
The surface finish of construction shall conform to the requirements of Clause B-9.2. Control on
the quality of material and works shall be exercised by the Engineer-in-Charge in accordance with
Clause B-9.3.
B-10.8.9 Arrangements for traffic
The provisions of Clause B-9.1 shall apply as regards the flow of traffic during construction.
B-10.8.10 Measurement of payment
Semi-dense Bituminous concrete shall be measured as finished work in square meters.
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B-10.9 BITUMINOUS CONCRETE

B-10.9.1 Description :
This work shall consist of constructing a single layer of 25-100 mm thick bituminous concrete on a
previously prepared bituminous base to the requirement of these specifications, to serve as a
wearing course.
B-10.9.2 Materials
(a) Binder
Clause B-10.8.2(a) shall apply.
(b) Coarse aggregates
Clause 10.8.2(b) shall apply, except that the aggregates shall satisfy the physical requirements of
Table B 10.9-1.
Table B 10.9-1: PHYSICAL REQUIREMENTS FOR COARSE AGGREGATES FOR
BITUMINOUS CONCRETE PAVEMENT LAYERS
Property Test Specification
Cleanliness (dust) Grain size analysis Max 5% passing 0.075 mm sieve

Particle shape Flakiness & Elongation Index Max 30% (combined)

Strength* Los Angeles Abrasion Value Max 30%

Aggregate Impact Value Max 24%

Polishing Polished Stone Value Min 55

Durability Soundness
Sodium Sulphate Max 12%
Magnesium Sulphate Max 18%

Water Absorption Water absorption Max 2%

Stripping Coating & Stripping of Bitumen Minimum retained coating 95%

Aggregate Mixtures

Water Sensitivity** Retained Tensile Strength Min 80%

(c) Fine aggregates

Clause B-10.8.2(c) shall apply.
(d) Filler
Clause B-10.8.2(d) shall apply.
(e) Aggregate gradation
The mineral aggregates, including mineral filler shall be so graded or combined so as to conform to
the grading set forth in Table B 10.9-2.
B-10.9.3 Mixture Design
(a) Requirement of mix
Apart from conformity with the grading and quality requirements of individual ingredients, the mix
shall meet the requirements set forth in Table B 10.9-3.
The requirements for minimum per cent voids in mineral aggregate (VMA) are set out in relevant
Table B 10.7-5.

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(b) Binder content
The binder content shall be optimized to achieve the requirements or the mixture set forth in Table
B 10.9-2 and the traffic volume as specified in the Contract. The Marshall method for determining
the optimum binder content shall be adopted.
(c) Job Mix Formula
The procedure for formulating the job mix formula shall be generally as specified in Clause B-
10.7.4 and the results of tests enumerated in Table B 10.9-3 shall be followed.
B-10.9.4 Construction operation
(a) Weather and seasonal limitations
Relevant guidelines for Bituminous Macadam, vide Clause B-10.4.6(A), shall apply.
TABLE 10.9-2: COMPOSITION OF BITUMINOUS CONCRETE PAVEMENT LAYERS
Grading 1 2
Nominal aggregate size 19 mm 13 mm
Layer Thickness 50-65 mm 30-45 mm
IS Sieve1 (mm) Cumulative % by weight of total aggregate passing
26.5 100 --
19.0 79-100 100
13.2 59-79 79-100
9.5 52-72 70-88
4.75 35-55 53-71
2.36 28-44 42-58
1.18 20-34 34-48
0.6 15-27 26-38
0.3 10-20 18-28
0.15 5-13 12-20
0.075 2-8 4-10
Bitumen content % by mass of
total mix2 5.0-6.0 5.0-7.0
Bitumen Grade (pen) 65 65
Notes: 1. The combined aggregate grading shall not vary from the low limit on one sieve to the high limit on the
adjacent sieve.
2. Determined by the Marshall method.
TABLE B 10.9-3: Requirements for Bituminous Concrete pavement layers
Minimum stability (kN at 600 C) 9.0
Minimum flow (mm) 2
Maximum flow (mm) 4
Compaction level (Number of blows) 75 blows on each of the two faces of the specimen
Percent air voids:
Percent voids in mineral aggregate (VMA) 3-6
Percent voids filled with bitumen (VFB) 65-75

(b) Preparation of base

Clause B-10.8.6(b) shall apply.
(c) Tack coat
Clause B-10.8.6(c) shall apply.
(d) Preparation of mix
Clause B-10.8.6(d) shall apply.

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(e) Spreading
Refer specification as per Clause B 10.4.6 (E).
(f) Rolling
Refer specification as per Clause B 10.7.5 (e).
B-10.9.5 Opening to traffic
Traffic may be allowed immediately after completion of the final rolling when the mix has cooled
down to the surrounding temperature.
B-10.9.6 Surface finish & Quality control of work
The surface finish of construction shall conform to the requirements of Clause B-9.2.
Control on the quality of materials and works shall be exercised by the Engineer-in-Charge in
accordance with Clause B-9.3.
B-10.9.7 Arrangement for traffic
The provisions of Clause B-9.1 shall apply as regards the flow of traffic during construction.
B-10.9.8 Measurement for payments
Bituminous Concrete shall be measured as finished work in square meters.

B-10.10 OPEN GRADED PREMIXED CARPET

(Using Penetration Grade Bitumen)

B-10.10.1 Description
This work shall consist of laying and compacting an open graded carpet of 20 mm thickness in a
single course composed of suitable small sized aggregates premixed with a bituminous binder on a
previously prepared base, in accordance with the requirements of these specifications to serve as a
wearing course.

B-10.10.2 Material
(a) Binder
The binder shall be bitumen of a suitable grade appropriate to the region, traffic, rainfall and other
environmental conditions as directed by the Engineer-in-Charge, and satisfying the requirements of
IS: 73.
(b) Aggregates
The aggregates shall conform to Clause B-10.4.3 except that the water absorption shall be limited
to a maximum of 1%.
(c) Proportioning of materials
The materials shall be proportioned as per quantities given in the Table B 10.10-1:
B-10.10.3 Construction operation
(a) Weather and seasonal limitation
Same as Clause B-10.6.3 (a)

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(b) Preparation of base
The underlying base on which the bituminous carpet is to be laid shall be prepared shaped and
conditioned to the specified lines, grade and cross section in accordance with the specifications as
detailed in Clause B-10.1 as directed by the Engineer-in-Charge. A prime coat, where needed, shall
be applied in accordance with Clause B-10.2 and as directed by the Engineer-in-Charge.
Table B 10.10-1: QUANTITIES OF MATERIALS REQUIRED PER 10 SQUARE METER OF
ROAD SURFACE FOR 20 mm THICK OPEN GRADE PREMIXED CARPET

Aggregates
a) Nominal stone size 13.2 mm.
(passing 22.4 mm. sieve and retained on 11.2 mm. sieve). 0.18 m3
b) Nominal stone size 11.2 mm.
(passing 13.2 mm. sieve and retained on 5.6 mm. sieve). 0.09 m3
Total : 0.27 m3
Binder
(quantities in terms of straight run bitumen)
a) For 0.18 m3 of 13.2 mm. nominal stone at 52 kg. per m3 9.5 kg.
b) For 0.09 m3 of 11.2 mm. nominal stone at 56 kg. Per m3 5.1 kg.
Total - 14.6 kg.
(c) Tack coat
A tack coat complying with the Clause B-10.3 shall be applied over the base preparatory to laying
of the carpet. Application of tack coat shall, however, not be necessary when the laying of carpet
follows soon after the provision of a bituminous base / leveling course, without opening to traffic.
(d) Preparation of premix
Mixer of approved type shall be employed for mixing the aggregates with the bituminous binder.
Hot Mix Plant and paver of appropriate capacity and type, if be used, shall be as described in
Clause B-10.6 (Bituminous Macadam)
The binder shall be heated to the temperature appropriate to grade of bitumen approved by the
Engineer-in-Charge in boilers of suitable design avoiding local over-heating and ensuring a
continuous supply.
The aggregates shall be dry and suitably heated to a temperature as directed by the Engineer-in-
Charge before these are placed in the mixer. After about 15 seconds of dry mixing, the heated
binder shall be distributed over the aggregate at the rate specified.
The mixing of binder with chippings shall be continued until the chippings are thoroughly coated
with binder. The mix shall be immediately transported from the mixer to the point of use in suitable
vehicles or wheel barrows. The vehicles employed for transport shall be clean and the mix being
transported covered in transit if so directed by the Engineer-in-Charge.
The temperature of binder at the time of mixing shall be in the range of 150º C to 163ºC and that of
aggregate in the range of 155º C to 163ºC. The discharge temperature of mix shall be between 130º
C and 160º C.
(e) Spreading and rolling
The premixed material shall be spread on the road surface with rakes to the required thickness and
camber or distributed evenly with the help of a drags spreader, without any undue loss of time. The
camber shall be checked by means of camber boards and inequalities evened out. As soon as
sufficient length of bituminous material has been laid, rolling shall commence with 8-10 tonnes
power rollers, preferably of smooth wheel tandem type or other approved plant.

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Rolling shall begin at the edges and progress towards the centre longitudinally, except that on the
super elevated portions it shall progress from the lower to upper edge parallel to the centre line of
the pavement.
When the roller has passed over the whole area once, any high spots or depressions which become
apparent shall be corrected by removing or adding premixed materials. Rolling shall then be
continued until the entire surface has been rolled to compaction and the roller marks eliminated. In
each pass of the roller, preceding track shall be overlapped uniformly by at least ⅓rd width. The
roller wheels shall be kept damp to prevent the premix from adhering to the wheels and being
picked up. In no case shall fuel/lubricating oil be used for this purpose. Excess use of water for this
purpose shall be avoided.
Rollers shall not stand on newly laid material while there is a risk that it will be deformed thereby.
Rolling operation shall be completed in every respect before the temperature of the mix falls below
100ºC.
The edges along and transverse of the carpet laid and compacted earlier shall be cut to their full
depth so as to expose fresh surface which shall be painted with a thin surface coat of appropriate
binder before the new mix is placed against it.
(f) Seal coat
A seal coat conforming to specifications as per Clause B-10.14 shall be applied to the surface
immediately after laying the carpet. No traffic shall be allowed on the road till the seal coat has
been placed.
B-10.10.4 Surface finish & quality control of work
Clause B-9.2 & B-9.3 shall apply.
B-10.10.5 Arrangement for traffic
Clause B-9.1 shall apply.
B-10.10.6 Measurements for Payment
Open graded premix Carpet shall be measured as finished work in square meters.

B-10.11 OPEN GRADED PREMIXED CARPET & SEAL COAT

(Using Cationic Bitumen Emulsion)
B-10.11.1 Description
This work shall consist of preparation, laying and compacting an open graded premix carpet of 20
mm thickness composed of suitable small sized aggregate premixed with cationic bitumen
emulsion placed on a previously prepared base in accordance with the requirements of these
specifications.
B-10.11.2 Material
(a) Binder
The binder shall be cationic bitumen emulsion of medium setting (MS) grade complying with IS:
8887 and having bitumen content 65 percent minimum by weight. For liquid seal coat RS grade
shall be used. However for premix seal coat, slow setting (SS) grade of cationic emulsion shall be
used.

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(b) Coarse aggregates
Clause B-10.8.2(b) shall apply.
(c) Fine aggregates
Fine aggregates for seal coat shall be crushed stone chips, clean, uncoated and free from clay dust
and other deleterious matter.
(d) Quantities of materials required
The materials shall be proportioned as per quantities given in Table B 10.11-1.
TABLE B 10.11-1: QUANTITIES OF MATERIALS REQUIRED PER 10 SQUARE METER OF
ROAD AREA
For premix carpet
13.2 mm. size aggregates
(Passing IS: 22.4 mm. sieve and retained on IS:11.2 mm. sieve) 0.18 m3

11.2 mm. size aggregates

(Passing IS:13.2 mm. sieve and retained on IS: 5.6 mm. sieve) 0.09 m3

Binder : 20 to 23 kg
For seal coat
(i) Liquid seal coat :
Crushed fine aggregates 6.7 mm. size
(Passing 11.2 mm. sieve and retained on 2.36 mm. sieve) 0.09 m3

Binder : 12 to 14 kg

(ii) Premix seal coat

Coarse sand or stone grit
(Passing 2.36 mm. sieve and retained on 180 micron sieve) 0.06 m3

Binder : 10 to 12 kg

B-10.11.3 Construction operation

(a) Weather limitations
Cationic bitumen emulsion should not normally be stored below 0ºC. However, premix carpet work
with cationic emulsion should be carried out only when the atmospheric temperature is above 10ºC.
(b) Preparation of Surface
The underlying surface on which the premix carpet is to be laid shall be prepared, shaped and
conditioned to the specified lines, grades and cross-sections in accordance with Clause B-10.1. The
cleaned surface can be finally washed with water, if it is readily available.
(c) Preparation of binder
Before opening cationic bitumen emulsion, drums should be rolled at slow speed, to and fro, for a
distance of about 10 meters to mix the contents properly.
(d) Tack coat
Cationic bitumen emulsion can be applied on wet road surface. Cationic bitumen emulsion should
be spread uniformly on the prepared base by mechanical sprayers. Tack coat should be applied not
earlier than 10 minutes before spreading the premix. On WBM surface water should be spread to
make the surface damp before applying tack coat.

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(e) Preparation of Premix

Premixing of cationic bitumen emulsion and aggregates can be done in a suitable mixer, such as
cold mixing plant as per IS:5435 (Revised) or concrete mixer or by payloaders in exceptional cases
if permitted by the Engineer-in-Charge. When using concrete mixer for preparing the premix 0.135
m3 (0.09 m3 of 13.2 mm. size and 0.045 m3 of 11.2 mm. size) of aggregates per batch may be used
as this quantity will cover 5 m2 of surface with 20 mm average thickness.
The aggregates shall be cleaned free from dust and dirt by washing with water in advance. The
coarse aggregate of 13.2 mm. size shall be placed into the mixer followed by 5 to 6.5 kg of cationic
bitumen emulsion and then the 11.2 mm size aggregate shall be added, followed by 5 to 6.5 kg of
cationic bitumen emulsion. After the materials are mixed uniformly the same should be unloaded
and immediately transported to the laying site in suitable vehicles. Too much mixing should be
avoided.
When mixed manually by shovels, with the approval of the Engineer-in-Charge, 0.06 m3 of
aggregates can be conveniently mixed in one heap with appropriate quantity of emulsion. It is
preferable to make the aggregates damp before mixing as it reduces the effort required for mixing
and also helps to get better coating of aggregates. The 13.2 mm size aggregates and emulsion are
mixed first and then the 11.2 mm size aggregates and remaining quantity of emulsion are added and
mixed. Too much mixing shall be avoided.
(f) Spreading
The premixed material should be spread within 10 minutes of applying the tack coat. The mix
remains easily workable for about 20 min after mixing; hence all leveling etc. should be done
within this time. The mix should be spread uniformly to the desired thickness, grades and cross
falls making due allowance for any extra quantity required to fill up depressions, if any. The cross
fall should be checked by means of camber boards and irregularities levelled out. Too much raking
is to be avoided.
(g) Rolling
The rolling shall start immediately after laying the premix. A smooth wheel tandem roller of 8-10
tonnes shall be used, unless other compaction methods are approved by the Engineer-in-Charge,
based on the results of laying trials, if necessary. While rolling, wheels of roller should be clean and
kept moist to prevent the premix from adhering to the wheels. In no case shall fuel/ lubricating oil
be used for this purpose. Use of water for this purpose shall be strictly limited to an absolute
minimum. Joints both longitudinal and transverse to the road sections laid and compacted earlier
shall be cut vertically to their full depth so as to expose fresh surface which shall be painted with a
thin surface coat of binder before the new mix is placed against it
(h) Seal Coat
A seal coat, liquid or premix type shall be applied 4 to 6 hours after laying the premixed carpet as
per IRC Specification.
B-10.11.4 Opening to traffic
Traffic should not be allowed over the premix surface with or without seal coat for 6 to 8 hours
after rolling. In case of single lane roads, traffic may be allowed at slow speed not exceeding 16
Km. per hour. If any premix material gets picked up, the spot shall be filled up by new mix. It is
preferable to open the road to traffic after 24 hours.
B-10.11.5 Measurement for payment
Open graded premix Carpet shall be measured as finished work in square meters.

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B-10.12 MIX SEAL SURFACING
B-10.12.1 Description
This work shall consist of laying and compacting close-graded premix surfacing in a single course
of 20 mm, composed of suitable aggregates premixed with a bituminous binder on a previously
prepared surface, in accordance with the requirements of these Specifications to serve as a wearing
course. Mix Seal surfacing shall be of Type A or Type B, as specified.
B-10.12.2 Materials
(a) Binder
Clause B-10.10.2(a) shall apply.
(b) Coarse aggregate
Clause B-10.10.2(b) shall apply.
(c) Fine aggregate
This will consist of crushed rock, quarry sands, natural gravel/ sand or a mixture of both. These
shall be clean, hard, durable, uncoated, dry and free from injurious, soft or flaky particles and
organic or deleterious substances.
(d) Aggregate gradation
The coarse and fine aggregates shall be so graded or combined as to conform to the grading set
forth in Table B 10.12-1.
(e) Proportioning of Materials
The total quantity of aggregates used for Type A or B mix seal surfacing shall be 0.27 cubic meter
per 10 square meter area. The quantity of binder used for premixing in terms of straight run
bitumen shall be 22.0 Kg. and 19.0 Kg. per 10 square meters for Type A and B surfacing
respectively.
B-10.12.3 Construction operations
Same specifications as per open graded premix carpet, is to be followed (Clause B-10.10).
TABLE B 10.12-1: AGGREGATE GRADATION FOR MIX SEAL SURFACING
I.S. Cumulative percent by weight of total aggregate passing
Sieve designation For Type A Mix Seal Surfacing For Type B Mix Seal Surfacing
13.2 mm. - 100
11.2 mm. 100 88-100
5.6 mm. 52-88 31-52
2.8 mm. 14-38 5-25
90 micron 0-5 0-5

B-10.12.4 Surface finish and quality control of work

The surface finish of construction shall conform to the requirements of Clause B-9.2. Control on
the quality of materials and works shall be exercised by the Engineer-in-Charge in accordance with
Clause B-9.3.
B-10.12.5 Arrangements for traffic
During the period of construction, flow of traffic shall be maintained to Clause B-9.1.
B-10.12.6 Measurement for payment
Mix seal surfacing, Type A or B shall be measured as finished work in square meters at a specified
thickness.

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B-10.13 SURFACE DRESSING

B-10.13.1 Description
This work shall consist of the application of one or two coats of surface dressing, each coat
consisting of a layer of bituminous binder sprayed on a base previously prepared base, followed by
a cover of stone chippings properly rolled to form a wearing course to the requirements of these
specifications.
B-10.13.2 Materials
(a) Binder
The binder shall have a kinematic viscosity lying in the range 1x104 to 7 x 105 centistokes at the
expected range of road surface temperatures at the construction site during the period of laying. The
type of binder to be used will be stated in the Contract documents and shall comply with one of the
following:
(i) Paving Bitumen conforming to IS : 73
(ii) Bitumen Emulsion conforming to IS: 8887
(b) Aggregates
The stone chippings shall consist of fairly cubical fragments of clean, hard, tough and durable rock
of uniform quality throughout. These shall be obtained by crushing stone, or other approved
materials. The chippings shall be free of elongated or flaky pieces, soft or disintegrated stone, salt,
alkali, vegetable matter, dust and adherent coatings. They shall conform to the quality requirements
of Table B 10.13-1.
Table B 10.13-1: GRADING REQUIREMENT FOR CHIPS FOR SURFACE DRESSING
Cumulative % by weight of total aggregate passing for the following
IS Sieve designation
nominal sizes (mm)
(mm)
19 13 10 6
26.5 100 - - -
19.0 85-100 100 - -
13.2 0-40 85-100 100 -
9.5 0-7 0-40 85-100 100
6.3 - 0-7 0-35 85-100
4.75 - - 0-10 -
3.35 - - - 0-35
2.36 0-2 0-2 0-2 0-10
0.60 - - - 0-2
0.075 0-1.5 0-1.5 0-1.5 0-1.5
Minimum 65% by weight of Passing 19mm, Passing 13.2mm, Passing 9.5mm, Passing 6.3mm,
aggregate retained 13.2mm retained 9.5mm retained 6.3mm retained 3.35mm

(c) Rates of spread of binder and chips

For the purpose of pricing the bill of quantities the rates of spread given in the Table B 10.13-2
shall be followed.
Table B 10.13-2: NORMAL RATE OF SPREAD FOR BINDERS & CHIPPINGS
Nominal Chipping Size.
Binder (penetration grade bitumen) kg/m2 Chips Cum/ m2
(mm)
19 1.2 0.015
13 1.0 0.010
10 0.90 0.008
6 0.75 0.004

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(d) Anti-stripping agent
Where the proposed aggregates fail to pass the stripping test then an approved adhesion agent may
be added to the binder in accordance with the manufacturer’s instructions. The effectiveness of the
proposed anti-stripping agent must be demonstrated by the Contractor, before approval by the
Engineer-in-Charge.
(e) Pre-coated chips
As an alternative to the use of an adhesion agent, the chips may be pre-coated before they are
spread except when the sprayed binder film is a bitumen emulsion. Pre-coating the chips may be
carried out in any one of the two methods:
(i) The chips are heated to 160o C and the paving bitumen is heated to its application temperature. The chips and
bitumen is then mixed together in a suitable mixer with 0.75 to 1.0% of bitumen by weight of chips and shall be
allowed to cure for at least one week or until they become non sticky and can be spread easily.
(ii) The chips are spread with a light application of creosote, diesel oil or kerosene at ambient temperature. This
spraying can be done in a concrete mixer or on a belt conveying the chips from stockpile to gritting trucks.
B-10.13.3 Construction Operations
(a) Weather & seasonal limitations
The work of laying shall not be taken up during rainy or foggy weather or when the base course is
damp or wet or during dust storm or when atmospheric temperature is in the shade of 10ºC or less.
(b) Preparation of Base
The base on which surface dressing is to be laid shall be prepared, shaped and conditioned to the
specified lines, grade and cross section in accordance with Clause B-10.1 and as directed by the
Engineer-in-Charge. Where the existing surface shows signs of fatting up, this shall be rectified.
The surface shall be thoroughly swept & scraped clean of dust and any other extraneous matter
before the spraying of binder. As necessary the cleaning shall be done first with hard brush, then
with soft brushes and finally by blowing with sacks or gunny bags. Mechanical broom and/or
compressed air or any other approved method or equipment may also be used.
(c) Application of Binder:
The application temperature for the grade of binder used shall be as per Table B 10.13-3:
TABLE B 10.13-3: SPRAYING TEMPERATURES FOR BINDERS
Whirling spray jets Slot jets
Binder grades
Min 0C Max 0C Min 0C Max 0C
Penetration Grades
400 / 500 160 170 140 150
280 / 320 165 175 150 160
180 / 200 170 190 155 165
80 / 100 180 200 165 175

(d) Application of stone chippings

Immediately after the application of binder, stone chippings in a dry and clean state shall be spread
uniformly on the surface preferably by means of a mechanical gritt sprayer otherwise manually, so
as to cover the surface completely. If necessary, the surface shall be broomed to ensure uniform
spread of chippings.
(e) Rolling
Rolling of the chips should preferably be carried out by a pneumatic tyred roller. Traditional steel
wheeled rollers tend to crush the aggregates and if their use cannot be avoided their weight should
be limited to 8-10 tonnes.

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Rolling shall commence at the edges and progress towards the centre except in super elevated
portions where it shall proceed from the inner edge to the outer. Each pass of the roller shall
uniformly overlap not less than 1/3rd of the track made in the preceding pass.
While rolling is in progress additional chippings shall be spread by hand in whatever quantities
required making up irregularities. Rolling shall continue until all aggregate particles are firmly
embedded in the binder and present a uniform closed surface.
(f) Application of Second coat of surface dressing
Where surface dressing in two coats is specified the second coat shall be applied immediately after
laying of the 1st coat. The construction operation for the 2nd coat shall be same as described in Para
(c) to (e) above.
B-10.13.4 Opening to traffic
Traffic shall not be permitted to run on any newly surface dressed area until the following day. In
special circumstances, however, the Engineer-in-Charge may open the road to traffic immediately
after rolling, but in such cases its speed shall be limited to 20 km per hour till the following day.
B-10.13.5 Surface finish and quality control of work
The surface finish of construction shall conform to the requirements of Clause B-9.2
B-10.13.6 Arrangement for traffic
During the period of construction, flow of traffic shall be maintained as per Clause B-9.1
B-10.13.7 Measurement for Payment
Each coat of surface dressing shall be measured as finished work in square meters.

B-10.14 SEAL COAT

B-10.14.1 Description
The work shall consist of application of a seal coat for sealing the voids in a bituminous surface
laid to the specified levels, grade and camber. Seal coat shall be of either of the two types as
specified below:-
Type A : Liquid seal coat comprising of an application of a layer of bituminous
binder followed by a cover of stone chippings.
Type B : Premixed seat coat comprising of a thin application of fine aggregates
premixed with bituminous binder.

B-10.14.2 Materials

(a) Binder :
The binder shall be bitumen of a suitable grade as directed by the Engineer-in-Charge and
conforming to the requirements of IS: 73, 217 or 454 as applicable or any other approved cutback
as applicable. The quantity of binder to be utilized in terms of straight run bitumen shall be 9.8
Kg/10 m2 and 6.8 Kg/10 m2area for Type A and Type B seal coat respectively.

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(b) Stone chippings for Type A seal coat
The stone chippings shall consist of angular fragments of clean, hard, tough and durable rock of
uniform quality throughout. They should be free of elongated or flaky pieces, soft or disintegrated
stone, vegetable of other deleterious matter.
Stone chippings shall be 6.7 mm size defined as 100 % passing through 11.2 mm. sieve and
retained on 2.36 mm. sieve. The quantity used for spreading shall be 0.09 m3 per 10 m2 area. The
chippings shall satisfy the quality requirements spelled out in Table under Clause10.7.2. (c) except
that the upper limit for water absorption value shall be 1 %.

(c) Aggregate for Type B seal coat

The aggregate shall be sand or grit and shall consist of clean, hard, durable, uncoated dry particles
and shall be free from dust, soft or flaky/elongated material, organic matter or other deleterious
substances. The aggregate shall pass 2.36 mm. sieve and be retained on 180 micron sieve. The
quantity used for premixing shall be 0.06 m3 per 10 m2 area.

B-10.14.3 Construction operation

(a) Preparation of base

The seal coat shall be applied immediately after laying the bituminous course which is required to
be sealed. Before application of seal coat materials the surface shall be cleaned free of any dust or
other extraneous matter.
(b) Construction of Type A seal coat
The binder shall be heated to 1500C to 1630C and sprayed at the rate specified on the dry surface in
a uniform manner with a self-propelled mechanical sprayer as described in the Manual for
Construction and Supervision of Bituminous Works (MORTH publication).
Immediately after the application of binder, stone chips, which shall be clean and dry shall be
spread uniformly at the rate specified on the surface preferably by means of a self-propelled or
towed mechanical grit spreader so as to cover the surface completely.
Immediately after application of the cover material, the entire surface shall be rolled with a 8-10
tonne smooth wheeled steel roller, 8-10 tonne static weight vibratory roller, or other equipment
approved by the Engineer-in-Charge after laying trials if required. Rolling shall continue until all
aggregate particles are firmly embedded in the binder and present a uniform closed surface.
(c) Construction of Type B seal coat
A mixer of appropriate capacity and type approved by the Engineer-in-Charge shall be used for
preparation of the mixed material. The plant shall have separate dryer arrangements for heating
aggregates.The binder shall be heated in boilers of suitable design, to the temperature appropriate to
the grade of bitumen approved by the Engineer-in-Charge. The aggregates shall be dry and suitably
heated to a temperature between 1500C and 1650C or as directed by the Engineer-in-Charge before
the same are placed in the mixer. Mixing of binder with aggregates to the specified proportions
shall be continued till the latter are thoroughly coated with the former.
The mix shall be immediately transported from the mixing plant to the point of use and spread
uniformly on the bituminous surface to be sealed. As soon as sufficient length has been covered
with the premixed material, the surface shall be rolled with 8-10 tonne smooth- wheeled rollers.
Rolling shall be continued till the premixed materials completely seals the voids in the bituminous
course and a smooth uniform surface as obtained.

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B-10.14.4 Opening to traffic

In the case of Type B seal coat, traffic may be allowed soon after final rolling when the premixed
material has cooled down to the surrounding temperature. However, as regards Type A seal coat,
traffic shall not be permitted to run on any newly sealed area until the following day. In special
circumstances, however the Engineer-in-Charge may open the road to traffic immediately after
rolling but in such cases its speed shall be limited to 16 Km/ hour till the following day.
B-10.14.5 Surface finish & quality control of work
The surface finish of construction shall conform to the requirement of Clause B-9.2. Control on the
quality of materials and works shall be exercised by the Engineer-in-Charge as per Clause B-9.3.
B-10.14.6 Measurement for Payment
Seal coat shall be measured as finished work in square meters at the thickness specified in the
Contract.

B-10.15 MASTIC ASPHALT

B-10.15.1 Description
This work shall consist of constructing a single layer of Bitumen Mastic wearing course for road
pavements and bridge decks. Mastic asphalt is an intimate homogeneous mixture of selected well
graded aggregates, filler and bitumen in such proportions as to yield a plastic and void less mass,
which when applied hot can be trowelled and floated to form a very dense impermeable surfacing.
The bitumen mastic shall preferably be laid over a Dense Bituminous Macadam base in case of
road pavements and over a Cement Concrete base in bridge decks.
B-10.15.2 Material
(a) Binder
The binder shall be paving grade bitumen of a suitable grade satisfying the requirements of given in
Table B 10.15-1.
TABLE B 10.15-1: REQUIREMENTS FOR PHYSICAL PROPERTIES OF BINDER

Sl. No. Characteristics Requirement Method of tests

1. Penetration at 25ºC 15+5* IS: 1203

2. Softening point , oC 65+10 IS: 1205
3. Loss on heating for 5h at 1630C , % by mass 2 % (Max) IS: 1212
4. Solubility in trichloroethylene, % by mass 95 % IS: 1216
5. Ash (mineral matter), % by mass 1% IS:1217
* In cold climate regions (temperature < 100C), a softer penetration grade of 30/40 may be used.
(b) Coarse aggregates
The coarse aggregates shall consist of hard durable crushed stones, which shall be clean, strong and
free of disintegrated pieces, organic and other deleterious matter and adherent coatings. They shall
satisfy the physical requirements given in Table B 10.7-1. The percentage and grading of the coarse
aggregates to be incorporated in the bitumen mastic depending upon the thickness of the finished
course shall be as per Table B 10.15-2.

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TABLE B 10.15-2: GRADE & THICKNESS OF MASTIC ASPHALT PAVING AND GRADING
OF COARSE AGGREGATE
Application Thickness range Nominal size of coarse Coarse aggregate content,
(mm) aggregates (mm) % by mass of total mix
Roads and carriageways 25-50 13 40+10
Heavily stressed areas i.e., 40-50 13 45+10
junctions and toll plazas
Nominal size of coarse aggregates 13 mm
IS Sieve (mm) Cumulative % passing by weight
19 100
13.2 88-96
2.36 0-5

(c) Fine aggregates

The fine aggregates shall be the fraction passing 2.36 mm and retained on 75 micron sieve
consisting of crusher run screening, natural sand or a mixture of both. These shall be clean, hard,
durable, uncoated, dry and free from soft or flaky pieces and organic or deleterious substances.
(d) Filler
The filler shall be limestone powder passing 75 micron sieve and shall have a minimum calcium
carbonate content of 80 per cent by weight when determined in accordance with IS:1514
The grading of the fine aggregates inclusive of filler shall be as given in Table B 10.15-3:
TABLE B 10.15-3: GRADING OF FINE AGGREGATES (INCLUSIVE OF FILLER)

IS Sieve Percentage by weight of aggregates

Passing 2.36 mm but retained on 0.60 mm 0-25

Passing 0.6 mm but retained on 0.212 mm 10-30

Passing 0.212 mm but retained on 0.075 mm 10-30

Passing 0.075 mm 30-55

B-10.15.3 Mix Design

(a) Hardness number
The bitumen mastic shall have a hardness number at the time of manufacture of 60 to 80 at 25ºC
prior to the addition of coarse aggregates and 10 to 20 at 25ºC at the time of laying after adding
coarse aggregates. The hardness number shall be determined in accordance with the method
specified in IS:1195-1978.
(b) Binder content
The binder content shall be so fixed as to achieve the requirements of the mix set forth in Clause B-
10.15.3.(a) and shall be in the range of 14 to 17 per cent by weight of total mix as indicated in
Table B 10.15-4.

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TABLE B 10.15-4: Composition of Bitumen Mastic Blocks without coarse aggregate

IS Sieve Percentage by weight of mastic asphalt
Minimum Maximum
Passing 2.36 mm but retained on 0.6 mm 0 22
Passing 0.6 mm but retained on 0.212 mm 4 30
Passing 0.212 mm but retained on 0.075 mm 8 18
Passing 0.075mm 25 45
Bitumen Content 14 17

(c) Job mix formula

The Contractor shall intimate the Engineer-in-Charge in writing at least 30 days before the start of
the work, the job mix formula proposed to be used by him for the work, indicating the source and
location of all materials, proportions of all materials such as binder and aggregates, single definite
percentage passing each sieve for the mixed aggregates and results of the tests recommended in
various Tables and Clauses of this Specification.
B-10.15.4 Construction Operations
(a) Weather and seasonal limitations: As per IRC Specifications.
(b) Preparation of the base
The base on which bitumen mastic is to be laid shall be prepared, shaped and conditioned to the
profile required and as directed by the Engineer-in-Charge. In case of a cement concrete base, the
surface shall be thoroughly power brushed clean and free of dust and other deleterious matter.
Under no circumstances shall bitumen mastic be spread on a base containing a binder which might
soften under high application temperatures. If any such spots or area are there, the same shall be cut
out and repaired before the bitumen mastic is laid.
(c) Tack coat
A tack coat as per Clause B-10.3 may be applied on the base upon the decision of the Engineer-in-
Charge.
(d) Preparation of bitumen mastic
Preparation of bitumen mastic consists of two stages. The first stage shall be mixture of filler and
fine aggregates and then heating the mixture to a temperature of 170ºC to 200ºC. Required quantity
of bitumen shall be heated to 170ºC to 180ºC and added to the heated aggregate. They shall be
mixed and cooked in an approved type of mechanically agitated mastic cooker for some time till
the materials are thoroughly mixed. Initially the filler alone is to be heated in the cooked for an
hour and then half the quantity of binder is added. After heating and mixing for some time, the fine
aggregates and the balance of binder are to be added and further cooked for about one hour. The
second stage is incorporation of coarse aggregates and cooking the mixture for a total period 3
hours. During cooking and mixing, care shall be taken to ensure that the contents in the cooker are
at no time heated to a temperature exceeding 210ºC.
In case where the material is not required for immediate use it shall be cast into blocks with filler,
fine aggregates and binder, weighing about 25 kgs each. These blocks when required to be used,
have to be reheated in the mechanically agitated cooker to a temperature of not less than 175ºC and
not more than 210ºC, thoroughly incorporated with the requisite quantity of coarse aggregates and
mixed continuously. Mixing shall be continued until laying operations are completed so as to
maintain the coarse aggregates in suspension. At no stage during the process of mixing shall the
temperature exceed 210ºC.
The bitumen mastic blocks (without coarse aggregates) shall show on analysis a composition within
the limits as given in Table above.

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The mix shall be transported to the laying site in a towed mixer transporter having arrangement for
stirring and keeping the mix hot during transportation.
(e) Spreading
The bitumen mastic shall be laid normally in one coat, at a temperature between 175 – 2100C and
sprayed uniformly by hand using wooden floats or by machine on the prepared and regulated
surface. The thickness of the mastic asphalt and the percentage of the aggregate shall be as per as
per Table B.10.15.2.2 or as specified by the Engineer-in-Charge. Where necessary, battens of the
requisite dimensions should be employed. Any blow holes that appeared in the surface shall be
punctured while the material is hot and the surface made good by further floating.
(f) Joints
It shall be ensured that all construction joints are properly and truly made. These joints shall be
made by warming existing bitumen mastic by the application of excess quantity of the hot mastic
mix which afterwards shall be trimmed to leave it flush with the surfaces on either side.
(g) Surface finish
The bitumen mastic surface can be slippery after floating; in order to provide resistance to skidding,
the bitumen mastic after spreading, while still hot, and in plastic condition shall be covered with a
layer of stone aggregate. This aggregate shall be 13.2 mm size (passing the 19.0 mm sieve and
retained on 9.5 mm sieve) or 9.5 mm size (passing the 13.2 mm sieve and retained on the 6.7 mm
sieve) subject to the approval of the Engineer-in-Charge. Hard stone chips of approved quality pre-
coated with bitumen at the rate of 2+0.4% of S-65 penetration grade. The addition of 2% of filler
complying with Table B 10.15-5 may be required.
Table B 10.15-5: Grading requirement for mineral filler
IS Sieve (mm) Cumulative percent passing by weight of total aggregate
0.60 100

0.30 95-100

0.075 85-100

The chips shall then be applied at the rate of 0.005 m3 per 10 m2 and rolled or otherwise pressed
into the surface of the mastic layer when the temperature of bitumen mastic is not less than 100ºC.
B-10.15.5 Opening to Traffic
The traffic may be allowed after completion of the work when the bitumen mastic’s temperature at
the mid depth of the completed layer has cooled has cooled down to the daytime maximum ambient
temperature.
B-10.15.6 Quality Control of Work
The type and grade of bitumen; the quality, grade and percentage of coarse and fine aggregates and
filler; the temperature control for heating the materials / mix, laying, floating and compacting,
hardness number of the bitumen mastic, etc., should be strictly followed as indicated in the various
Clauses of this Specification or as directed by the Engineer-in-Charge.
The quality control tests for coarse and fine aggregates shall be exercised by the Engineer-in-
Charge in accordance with IRC specifications. The surface of the bitumen mastic tested with a
straight edge 3.0 m long, placed parallel to the centre line of the carriageway shall have no
depression greater than 7 mm. The same limit shall also apply in case of transverse profile when
tested with a camber template.

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B-10.15.7 Arrangements for Traffic

During the period of construction, arrangement of traffic shall be done as per direction of Engineer-
in-Charge.
B-10.15.8 Measurement for Payment
Mastic asphalt shall be measured as finished work in square meters at a specified thickness.

B-10.16 SLURRY SEAL

B-10.16.1 Scope
Slurry seals are mixtures of fine aggregate, Portland cement filler, bitumen emulsion and additional
water. When freshly mixed, they have a thick consistency and can be spread to a thickness of 1.5 –
5 mm. They may be used to seal cracks, arrest fretting and fill voids and minor depressions, to
provide a more even riding surface or a base for further treatment; they may also be used on top of
a single coat surface dressing.
B-10.16.2 Materials
The materials for slurry seal immediately prior to mixing shall conform to the following
requirements:
(a) Emulsified Bitumen
The emulsified bitumen shall be a cationic rapid setting type as approved by the Engineer-in-
Charge, conforming to the stipulations of IS: 8887. Generally, emulsions for slurry seals should be
capable of producing a slurry that will develop early resistance to traffic and rain and is sufficiently
stable to permit mixing with the specified aggregate, without breaking during the mixing and laying
processes.
If approved by the Engineer-in-Charge, a slow setting emulsion may be used.
(b) Water
Water shall be of such quality that the bitumen will not separate from the emulsion before the slurry
seal is in place. The pH of water must lie between 4 and 7 and if the total dissolved solids in the
water amount to more than 500 ppm, the Engineer-in-Charge may reject it, or order the Contractor
to conduct a trial emulsion mix to demonstrate that it does not cause early separation.
(c) Aggregate
The aggregate shall be crushed rock, or slag and may be blended, if required, with clean, sharp,
naturally occurring sand free from soft pieces and organic and other deleterious substances to
produce a grading as given in Table B 10.16-1.
The aggregates shall meet the requirements of film stripping test (IS: 6241), and a suitable amount
and type of anti-stripping agent added, as may be needed.
(d) Additives
It is usual to use ordinary Portland cement, hydrated lime or other additives to control consistency,
mix segregation and setting rate. The proportion of the additive should not normally exceed 2% by
weight of dry aggregates.

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B-10.16.3 Mixture Design
A range of residual binder contents for each aggregate grading is given in table B 10.16-1. The
optimum mixture design for the aggregate, additive, water and bitumen emulsion mixture should be
determined in accordance with ASTM D 3910.
TABLE B 10.16-1: AGGREGATE GRADING, BINDER CONTENT & APPROXIMATE
COVERAGE RATE
Sieve size (mm) Percentage by mass passing finished thickness of sealing
5 mm 3 mm 1.5 mm
9.5 100 - -
4.75 90-100 100 -
3.35 - 80-100 100
2.36 65-90 75-100 95-100
1.18 45-70 55-90 70-95
0.600 30-50 35-70 55-75
0.300 18-30 20-45 30-50
0.150 10-21 10-25 10-30
0.075 5-15 5-15 5-15

Quantity of residual binder,

7.5 – 13.5 10 - 16 12 - 20
percentage by mass of aggregate

Approx coverage rate (kg/m2) 8 - 15 4-6 2-4

B-10.16.4 Construction Operations

(a) Surface preparation
Any necessary remedial work to the road surface and structure shall be completed either prior to or
as part of the Contract or agreed as acceptable by the Engineer-in-Charge. Before slurry seal is
applied, street furniture and, where directed by the Engineer-in-Charge, road markings shall be
masked against the passage of the spreader box or the tools used for hand laying. Any packed mud
or other deposits on the surface shall be removed. All organic growth shall be removed by suitable
means, and the surface hall be swept free of all loose material.
(b) Tack Coat
If required by the Engineer-in-Charge, a tack coat may be applied prior to the slurry seal, with or
without grit or chips, in order to seal the existing subs-strata and enhance the bond to the existing
road surface. Unless otherwise agreed by the Engineer-in-Charge, the rate of spread of tack coat
shall be 0.15 to 0.30 litres/ m2 for bituminous surfaces and 0.40 to 0.60 litres/ m2 for concrete
surfaces.
(c) Mixing and transportation of mixture
Mixing may be by hand, concrete mixer or other mixer which effectively coats the aggregate
uniformly and produces a slurry seal of suitable consistency for satisfactory laying. For large areas,
a bulk transit concrete mixer may be used into which the ingredients (including water) are
measured and mixed as the mixer travels to the area to be treated. A screed box fitted with an
adjustable rubber screed should be towed by the mixer which feeds it during laying.
The special mobile mixing machine, when used, shall be capable of uniform application to provide
a continuous surface without ridges or segregation. Before laying begins, the Contractor shall
provide the Engineer-in-Charge with a test certificate showing test results for rate of applications
carried out under the supervision of a competent authority, demonstrating that the machine has been

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tested, using the system to be used in the Contract, not more than six weeks before the
commencement of the work.
Where the material is to be hand laid, the slurry seal may be supplied to the site premixed in
suitable containers and steps shall be taken to ensure that the material in each container is of an
even consistency throughout the container immediately prior to use.
(d) Application
Transverse joints for machine laid areas shall be formed with spreading, starting and finishing on a
protective strip not less than 100 mm wide at each end of the lane length being treated. Transverse
joints shall be formed such that there shall be no ridges or bare strips.
Unless otherwise approved by the Engineer-in-Charge, longitudinal joints shall coincide with lane
markings. Longitudinal joints shall be formed such that there shall be no ridges or bare strips.
Hand work around street furniture and other obstructions should meet the same performance
requirements and form a homogeneous surface with the rest of the treated carriageway.
Footways and other confined areas may be spread by hand using squeegees and brooms. Transverse
joints shall be formed with spreading, starting, and finishing on a protective strip not less than 100
mm wide at each end of the lane length being treated. Transverse joints shall be formed such that
there shall be no ridges or bare strips. Kerb edges and other areas not being treated shall be suitably
masked with adhesive masking material. Footways shall be finished by dragging a dampened
broom transversely over the footway under its own weight.
All voids, cracks and surface irregularities shall be completely filled. In warm dry weather the
surface, immediately ahead of spreading, shall be slightly dampened by mist water spray applied
mechanically, or for hand laying by a hand operated pressure sprayer, unless otherwise approved by
the Engineer-in-Charge.
(e) Rolling
The need for rolling shall be as instructed by the Engineer-in-Charge. Where rolling is required, a
pneumatic-tyred roller having an individual wheel load between 0.75 and 1.5 tonnes shall be used,
or as may be directed by the Engineer-in-Charge. Rolling shall commence as soon as the slurry has
set sufficiently to ensure that rutting or excessive movement will not occur
(f) Opening to Traffic
Masking shall be removed after the slurry seal has been applied, without damage to the edge of the
surfacing, and before opening the road or footway to traffic.
The Contractor shall remove surplus aggregate from the treated areas using a method agreed by the
Engineer-in-Charge. The Contractor shall monitor the slurry seal closely for a minimum period of 2
hours and if necessary the lane shall be swept again. The monitoring shall continue until the slurry
seal has reached sufficient stability to carry unrestricted traffic. If there are signs of distress, the
Engineer-in-Charge shall require the Contractor to reinstate traffic safety and management
procedures or other such remedial
Action where necessary in order to prevent further damage.
Further operations to remove subsequently loosened aggregate shall be carried out over the next 48
hours. The areas treated and adjacent side roads, footways and paved areas shall be kept
subsequently free of loose aggregates for a period of 30 days after completion of the work.

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B-10.16.5 Surface Finish & Quality Control of Work
Generally, the surface finish of the completed construction shall conform to the requirements of
Clause 9.2.1. For control of the quality of materials supplied and the works carried out, the relevant
provisions of Clause 9.2 shall apply.
In addition, the finished slurry shall have a uniform surface texture throughout the work, without
variations of texture within the lane width, or from lane to lane, due to segregation of aggregates, or
due to variations in the emulsions/water content of the mixture. The finished surface shall be free
from blow holes and surface irregularities in excess of 3 mm beneath a 1 meter straight edge due to
scraping, scabbing, dragging, droppings, excess overlapping or badly aligned longitudinal or
transverse joints, damage by rain or frost, or other defects which remain 24 hours after laying.
B-10.16.6 Measurement for Payment:
Slurry seal shall be measured as finished work as specified, in square meters.

B-10.17 FOG SPRAY

B-10.17.1 Scope
Fog spray is a very light application of low viscosity bitumen emulsion for purpose of sealing
cracks less than 3 mm wide or incipient fretting or disintegration in an existing bituminous
surfacing, and to help reduce loosening of chips by traffic on newly finished surface dressing.
B-10.17.2 Material
The bitumen emulsion shall be as specified in the Contract or as instructed by the Engineer-in-
Charge. The emulsion shall be SS-1h or as approved by the Engineer-in-Charge. Before use the
emulsion shall be diluted, 1 part emulsion to 1 part water. Emulsion of lower viscosity does not
require to be diluted. Because of their low viscosity they can be used as soon as possible before
delivery. If this is not possible, the drums should be very thoroughly rolled before use.
B-10.17.3 Weather and Seasonal Limitations
Spraying shall not take place when the temperature is below 100o C, nor in windy and dusty
conditions, nor when it is raining or the surface to be sprayed is wet.
B-10.17.4 Construction Operations
(a) Equipment
The fog spray shall be applied by means of a self-propelled or towed bitumen pressure sprayer
complying with the requirements of the Manual for Construction and Supervision of Bitumen
Works. The spray bar should be protected from gusts of wind by means of a hood.
(b) Preparation of Surface
The surface on which the fog spray is to be applied shall be thoroughly cleaned with compressed
air, scrubbers, etc. The cracks shall be cleaned with a pressure air jet to remove all dirt, dust, etc.
(c) Application
The fog seal shall be applied @ 0.5 – 1.0 litre/m2, using equipment such as pressure tank, flexible
hose and spray bar.

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(d) Blinding
If specified in the Contract or ordered by the Engineer-in-Charge, the fog spray shall be blinded
with graded grit of 3 mm size and under, coated with about 2% of the emulsion by weight. The pre
coated shall be allowed to be cured for at least one week or until they become non-sticky and can
be sprayed easily.
B-10.17.5 Quality Control of Work
For control of the quality of materials supplied and the works carried out, the relevant provisions of
Clause 9.3 shall apply.
B-10.17.6 Measurement for Payment
Fog spray and blinding (if used) shall be measured in terms of surface area of application, for the
area covered, in square meters.

B-10.18 MODIFIED BINDER

B-10.18.1 Scope
Modified binders comprise a base binder, to which is added either natural rubber, crumb rubber or a
polymer such as Styrene-Butadiene-Styrene (SBS), Ethylene-Vinyl-Acetate (EVA) or Low Density
Polyethylene (LDPE). The purpose is to achieve a high performance binder with improved
properties, particularly at extremes of temperature.

B-10.18.2 Materials
(a) Base Binder
The base binder into which the modifier is incorporated shall conform to IS: 73. The choice of
grade shall be such that it is compatible with the modifier and, when mixed shall have the
properties described in Tables 500-44 and 500-45 under Clause 521 of Specifications for Road &
Bridge Works (4th Revision).
Table B 10.18-1: Requirements of Polymer Modified Binder (IS: 9382-1979)
Grade Method of
Designation
CRMB-60 CRMB-55 CRMB-50 Test
Penetration at 250C, 0.1 mm,100g, 5 sec. 50-70 50-60 40-60 IS:1203-1978

Softening Point, (R & B), 0C,Minimum 50 55 60 IS:1205-1978

Elastic recovery at Half Thread in Ductilometer at 40 35 30 ASTM

150C, % Minimum D5976-1996

Reduction in Penetration at 250C, %, Maximum 60 60 60 IS:1203-1978

Increase in Softening Point (R & B), 0C, Maximum 5 5 5 IS: 1205-1978

Elastic Recovery of Residue of Half Thread in 25 20 15 ASTM

Ductilometer at 150C, % Minimum D5976-1996

CRMB – Crumb Rubber Modified Bitumen

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(b) Modifier
The modifier shall be a natural rubber, crumb rubber or any other polymer which is compatible
with the base binder and which allows the properties as given in Tables B 10.18-1 to be achieved.
For further details, IRC: SP-53 may be referred to. The modifier, in the required quantity shall be
blended at the refinery or at the site plant capable of producing modified binder.
For other details of modified binder, Clause 521 of Specifications for Road & Bridge Works (4th
Revision) of MoRT&H may be referred to.

B-11 SPECIFICATION FOR BRIDGE AND CULVERT WORKS

B-11.1 General
Specification for all Bridges and Culverts works should conform to those laid down in the I.R.C.
Bridge Codes and Specifications for Roads & Bridge Works published by I.R.C. on behalf of
Ministry of Road Transport & Highways, Govt. of India.
Determination of the proportions of cement, aggregate and water to attain the required strength
shall be made as follows:-
(a) By designing the concrete mix designated as “Design Mix Concrete.”
(b) By adopting a nominal mix for the concrete termed as “Nominal Mix Concrete.”
For all items of concrete in any Structural portion of the road pavement, Culvert and Bridge or its
components, design mix concrete shall be used unless otherwise specified.
The mix proportion shall be selected to ensure that the workability of the fresh concrete is suitable
for the conditions of handling and placing so that after compaction it surrounds all reinforcements
and completely fills the formwork. When concrete is hardened it shall have the required strength,
durability and surface finish.
In proportioning concrete, the quantity of both cement and aggregates should be determined by
weight.
The proportioning of concrete mixes shall be designed as per the relevant stipulations of IS: 10262
to have a target mean strength defined as {(fck + 1.65) x S} in case of Design Mix Concrete where
‘S’ is the standard deviation. The minimum cement content required in cement concrete to ensure
durability under specified conditions of exposure shall be as per Table B 11.1-1 for Plain Concrete,
Reinforced Concrete and Prestressed Concrete :-
TABLE B 11.1-1: MINIMUM CEMENT CONTENT FOR DIFFERENT TYPES OF CONCRETE
PCC Members RCC Members PSC Members
Minimum Maximum Minimum Maximum Minimum Maximum
Exposure cement water cement water cement water
content cement content cement content cement
Kg/m3 Ratio Kg/m3 Ratio Kg/m3 Ratio
Normal 250 0.50 360 0.45 400 0.40
Severe 310 0.45 400 0.40 400 0.40
Notes:
(a) For Plain concrete and Reinforced concrete the minimum cement content is based on 20 mm. nominal size of
aggregate. For 40 mm and larger size of aggregate, it may be reduced suitably but the reduction shall not be
more than 10 percent
(b) For underwater concreting, the cement content shall be increased by 10 %.

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(c) Severe conditions of exposure shall mean alternate wetting and drying due to sea spray, alternate wetting and
drying combined with freezing and buried in soil having corrosive effect.
(d) Moderate conditions of exposure shall mean other than those mentioned in 3 above.
(e) The cement content shall be as low as possible but not less than the quantity specified above. In no case shall it
exceed 540 kg per m3 of concrete.

B-11.2 SOURCES OF MATERIAL

The Contractor shall notify the Engineer of his proposed sources of materials prior to delivery. If it
is found after trial that sources of supply previously approved do not produce uniform and
satisfactory products, or if the product from any other source proves unacceptable at any time, the
Contractor shall furnish acceptable material from other sources at his own expense.

B-11.3 BRICKS
Burnt clay bricks shall conform to the requirements of IS: 1077, except that the minimum
compressive strength when tested flat shall not be less than 8.4 MPa for individual bricks and 10.5
MPa for average of 5 specimens. They shall be free from cracks and flaws and nodules of free lime.
The brick shall have smooth rectangular faces with sharp corners and emit a clear ringing sound
when struck. The size may be according to local practice with a tolerance of + 5 per cent.

B-11.4 STONES
Stones shall be of the type specified. It shall be hard, sound, free from cracks, decay and weathering
and shall be freshly quarried from an approved quarry. Stone with round surface shall not be used.
The stones, when immersed in water for 24 hours, shall not absorb water by more than 5 per cent of
their dry weight when tested in accordance with IS: 1124.
The length of stones shall not exceed 3 times its height nor shall they be less than twice its height
plus one joint. No stone shall be less in width than the height and width on the base shall not be
greater than three-fourth of the thickness of the wall nor less than 150 mm.

B-11.5 SAND / FINE AGGREGATES

For masonry work, sand shall conform to the requirements of IS: 2116
For plain and reinforced cement concrete (PCC and RCC) or prestressed concrete (PSC) works,
fine aggregate shall consist of clean, hard, strong and durable pieces of crushed stone, crushed
gravel, or a suitable combination of natural sand, crushed stone or gravel. They shall not contain
dust, lumps, soft or flaky, materials, mica or other deleterious materials in such quantities as to
reduce the strength and durability of the concrete, or to attack the embedded steel.
Motorised sand washing machines should be used to remove impurities from sand. Fine aggregate
having positive alkali-silica reaction shall not be used. All fine aggregates shall conform to IS: 383
and tests for conformity shall be carried out as per IS: 2386, (Parts I to VIII).
The Contractor shall submit to the Engineer the entire information indicated in Appendix A of IS:
383. The fineness modulus of fine aggregate shall neither be less than 2.0 nor greater than 3.5.
Sand / fine aggregate for structural concrete shall conform to the grading requirements vide Table B
11.5-1:

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Table B 11.5-1:GRADING REQUIREMENTS FOR FINE AGGREGATES

Per cent by Weight Passing the Sieve

IS Sieve Size
Zone I Zone II Zone III
10 mm 100 100 100
4.75 mm 90-100 90-100 90-100
2.36 mm 60-95 75-100 85-100
1.18 mm 30-70 55-90 75-100
600 micron 15-34 35-59 60-79
300 micron 5-20 8-30 12-40
150 micron 0-10 0-10 0-10

B-11.6 STEEL
(A) Cast Steel
The use of cast steel shall be limited to bearings and other similar parts. Steel for castings shall
conform to Grade 280-520N of IS: 1030. In case where subsequent welding is unavoidable in the
relevant cast steel components, the letter N at the end of the grade designation of the steel casting
shall be replaced by the letter W. 0.3 % to 0.5 % copper may be added to increase the corrosion
resistance properties.
(B) Stainless Steel
Stainless steel shall be authentic chromium-nickel steel, possessing rust, acid and heat resistant
properties conforming to IS:6603 and IS:6911. Mechanical properties/grade for such stainless steel
shall be as specified by the accepting authority, but in no case be inferior to mild steel. Generally,
stainless steel is available as per AISI grades. AISI 304 which is equivalent to grade 04Cr18Ni110
of IS:6911 satisfies the requirements of mechanical properties of structural steel. Other grades of
stainless steel for specific purposes may be provided as per specific requirements. For application
in adverse/corrosive environment, stainless steel shall conform to AISI 316L or 02G17 Ni Mo2 of
IS: 6911.

(C) Reinforcement/ Un-tensioned Steel

For plain and reinforced cement concrete (PCC and RCC) or prestressed concrete (PSC) works, the
reinforcement/un-tensioned steel as the case may be shall consists of the following grades of
reinforcing bars.
Table B 11.6-1 : GRADES OF REINFORCING BARS
Grade Designation Bar type conforming to IS Characteristic Elastic Modulus
Specification Strength (MPa) (GPa)
S 240 IS:432 Part I: Mild Steel Bar 240 200

S 415 IS: 1786 : High Yield Strength 415 200

Deformed (HYSD) Bars.

S 500 -Do- 500 200

Note: Wire fabrics conforming to IS: 1566 and TMT bars conforming to IS:1786 can also be used.
All steel shall be procured from original producers, no re-rolled steel shall be incorporated in the
work.

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Only new steel shall be delivered to the site. Every bar shall be inspected before assembling on the
work and defective, brittle or burnt bar shall be discarded. Cracked ends of bars shall be discarded.

(D) Steel for Pre-stressing

The Pre-stressing steel shall conform to either of the following:
(i) Plain hard drawn steel wire conforming to IS: 1785 (Pt.I) and IS: 1785 (Pt.II)
(ii) Cold drawn indented wire conforming to IS: 6003
(iii) High tensile steel bar conforming to IS:2090
(iv) Uncoated stress relieved strands conforming to IS: 6006.

(E) Structural Steel

Unless otherwise permitted herein, all structural steel shall before fabrication comply with the
requirements of the following Indian Standards:
IS:1148 : Hot rolled rivet bars (upto 40mm dia) for structural purposes
IS:1149 : High tensile rivet bars for structural purposes
IS:1161 : Steel tubes for structural purposes
IS: 4923 : Hollow Steel sections for structural use
IS:11587 : Structural weather resistant steel
IS: 808 : Specifications for Rolled Steel Beam, Channel and Angle Sections
IS:1239 : Mild Steel Tubes
IS:1730 : Dimension for Steel Plate, sheet and strip for structural and general
engineering purposes
IS:1731 : Dimension for Steel flats for structural and general engineering
purposes
IS:1732 : Dimension for round and square steel bars for structural and general
engineering purposes
IS:1852 : Rolling and cutting tolerances for hot rolled steel products
IS: 226 : Structural Steel (Standard Quality).
IS: 961 : Structural steel (High Tensile)
IS: 2062 : Weldable Structural Steel
IS: 8500 : Weldable Structural Steel (medium & high strength qualities)

B-11.7 WATER
Water used for mixing and curing shall be clean and free from injurious amounts of oils, acids,
alkalis, salts, sugar, organic materials or other substances that may be deleterious to concrete or
steel. Potable water is generally considered satisfactory for mixing concrete. Mixing and curing
with sea water shall not be permitted. As a guide, the following concentrations represent the
maximum permissible values:
(a) To neutralize 200 ml sample of water, using phenolphthalein as an indicator, it should not
require more than 2 ml of 0.1 normal NaOH.
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(b) To neutralize 200 ml sample of water, using methy1 orange as an indicator, it should not
require more than 10 ml of 0.1 normal HCl.
(c) The permissible limits for solids shall be as follows when tested in accordance with
IS:3025.
Organic : 200 mg per liter (max.)
Inorganic : 3000 mg per liter (max.)
Sulphates (SO4) : 500 mg per liter (max.)
Chloride (Cl) : 500 mg per liter (max.)
Suspended matters : 2000 mg per liter (max.)
In case of structures of lengths 30m and below, the permissible limit of chlorides may be
increased up to 1000 mg/lit.
All samples of water (including potable water) shall be tested and suitable measures taken
where necessary to ensure conformity of the water to the requirements stated herein.
(d) The pH value shall not be less than 6.

B-11.8 TIMBER
The timber used for structural purposes shall conform to IS:883.

B-11.9 CONCRETE ADMIXTURES

Admixtures are materials added to the concrete before or during mixing with a view to modify one
or more of the properties of concrete in the plastic or hardened state.
Concrete admixtures are proprietary items of manufacture and shall be obtained only from
established manufacturers with proven track record, quality assurance and full fledged laboratory
facilities for the manufacturer and testing of concrete. Admixture shall conform to IS: 9103.
The Contractor shall provide the following information concerning each admixture after obtaining
the same from the manufacturer:
(a) Normal dosage and detrimental effects, if any, of under dosage and over dosage.
(b) The chemical names of the main ingredients in the admixtures.
(c) The chloride content, if any, expressed as a percentage by the weight of the admixture.
(d) Value of dry material content, ash content, relative density of the admixture which can be
used for Uniformity Tests.
(e) Whether or not the admixture leads to the entertainment of air when used as per the
manufacturer’s recommended dosage, and if so to what extent.
(f) When two or more admixture is proposed to be used in any one mix confirmation as to
their compatibility.
(g) There would be no increase in risk of corrosion of the reinforcement or other embedment
as a result of using the admixture.

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B-11.10 CEMENT
For concrete constructions the following type of cements are used subject to the approval of the
Engineer-in-Charge:
(a) Ordinary Portland Cement conforming to IS:269 (33 Grade)
(b) Ordinary Portland Cement conforming to IS:8112 (43 Grade)
(c) Ordinary Portland Cement conforming to IS:12269 (53 Grade)
(d) Rapid Hardening Portland Cement conforming to IS:8041
(e) Portland Blast Furnace Slag Cement conforming to IS:455
For high strength concrete high strength Portland cement conforming to IS: 8112 & 12269 should
be used.

B-11.11 COARSE AGGREGATE

For plain and reinforced cement concrete (PCC & RCC) or prestressed concrete(PSC) works,
coarse aggregate shall consists of clean, hard, strong, dense, non-porous and durable pieces of
crushed stone, crushed gravel, natural gravel or a suitable combination or a suitable combination
thereof or other approved inert material. They shall not consist pieces of disintegrated stones, soft,
flaky, elongated particles, salt, alkali, vegetable matter or other deleterious matter in such quantities
as to reduce the strength and durability of concrete, or to attack the steel reinforcement. All coarse
aggregates shall conform to IS: 383 and tests for conformity shall be carried out as per IS: 2386,
Part I to VIII.
Table B 11.11-1: REQUIREMENTS OF COARSE AGGREGATES
IS Sieve Size Percent by Weight Passing the Sieve
(mm) 40 mm 20 mm 12.5 mm
63 100 -- --
40 95-100 100 --
20 30-70 95-100 100
12.5 -- -- 90-100
10 10-35 25-55 40-85
4.75 0-5 0-10 0-10
The preferred nominal size of aggregates is 20 mm for reinforced and prestressed concrete.
However, larger sizes upto 40 mm may be permitted in special ceases when there is no restriction
to flow of concrete in a section.
The maximum value for flakiness index for coarse aggregates shall not exceed 35 %. The coarse
aggregate shall satisfy the requirement of grading vide Table B 11.11-1:

B-11.12 FORMWORK

B-11.12.1 Description
Formwork shall include all temporary or permanent forms required for forming the concrete of the
shape, dimensions and surface finish as shown on the drawing or as directed by the Engineer-in-
Charge, together with all props, staging, centering, scaffolding and temporary construction required
for their support. The design, erection and removal of formwork shall conform to IRC: 87
“Guidelines for Design and Erection of Falsework for Road Bridges”.

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B-11.12.2 Materials
All materials shall comply with the requirements of IRC: 87. Materials and components used for
formwork shall be examined for damage or excessive deterioration before use/re-use and shall be
used only if found suitable after necessary repairs. In case of timber formwork, the inspection shall
not only cover physical damages but also signs of attacks by decay, rot or insect attack or the
developments of splits.
Forms shall be constructed with metal or timber. The metal used for forms shall be of such
thickness that the forms remain true to shape. All bolts should be countersunk. The use of approved
internal steel ties or steel or plastic spacers shall be permitted. Structural steel tubes used as support
for forms shall have a minimum wall thickness of 4 mm. other materials conforming to the
requirements of IRC: 87 may also be used if approved by the Engineer-in-Charge.

B-11.12.3 Design of Formwork

The Contractor shall furnish the design and drawing of complete formwork (i.e., the forms as well
as their supports) for approval of the Engineer-in-Charge before any erection is taken up. If
propriety system of formwork is used, the Contractor shall furnish detailed information to the
Engineer-in-Charge for approval.
Notwithstanding any approval or review of drawing and design by the Engineer-in-Charge, the
Contractor shall be entirely responsible for the adequacy and safety for formwork.
The design of the formwork shall conform to provisions of IRC:87. It shall ensure that the forms
can be conveniently removed without disturbing the concrete. The design shall facilitate proper and
safe access o all parts of formwork for inspection.
In the case of prestressed concrete superstructure, careful consideration shall be given to
redistribution of loads on props due to Pre-stressing.

B-11.12.4 Workmanship
The formwork shall be robust and strong and the joints shall be leak-proof. Balli shall not be used
as staging. Staging must have cross bracings and diagonal bracings in both directions. Staging shall
be provided with an appropriate designed base plate resting on firm strata.
The number of joints in the formwork shall be kept to a minimum by using large size panels. The
design shall provide for proper “soldiers” to facilitate alignment. All joints shall be leak proof and
must be properly sealed. Use of PVC JOINT sealing tapes, foam rubber or PVC T-section is
essential to prevent leakage of grout. As far as practicable, clamps shall be used to hold the forms
together. Where use of nails is unavoidable, minimum number of nails shall be used and these shall
be left projecting so that they can be withdrawn easily. Use of double headed nails shall be
preferred. Use of ties shall be restricted, as far as practicable. Wherever ties are used they shall be
used with HDPE sheathing so that the ties are easily removed. No parts prone to corrosion shall be
left projecting or near the surface. The sheathing shall be grouted with cement mortar of the same
strength as that of the structure.
Unless otherwise specified, or directed, chamfers or fillets of sizes 25 mm x 25 mm shall be
provided at all angles of the formwork to avoid sharp corners. The chamfers, beveled edges and
mouldings shall be made in the formwork itself. Opening for fixtures and other fittings shall be
provided in the shuttering as directed by the Engineer-in-Charge.
Shuttering for walls, sloping members and thin sections of considerable height shall be provided
with temporary openings to permit inspection and cleaning out before placing of concrete.

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The formwork shall be constructed with pre-camber to the soffit to allow for deflection of the
formwork. Pre-camber to allow for deflection of formwork shall be in addition to that indicated for
the permanent structure in the drawings.
Where centering trusses or launching trusses are adopted for casting of superstructure, the joints of
the centering trusses, whether welded, riveted or bolted should be thoroughly checked periodically.
Also, various members of the centering trusses should be periodically examined for proper
alignment and unintended deformation before proceeding with the concreting. They shall also be
periodically checked for any deterioration in quality due to steel corrosion.
The formwork shall be so made as to produce a finished concrete true to shape, line and levels and
dimensions as shown on the drawings, subjected to tolerances specified in respective sections of
these specifications , or as directed by the Engineer-in-Charge.
Where metal forms are used, all bolts and rivets shall be countersunk and well ground to provide a
smooth, plane surface. Where timber is used it shall be well seasoned, free from loose knots,
projecting nails, splits or other defects that may mar the surface of concrete.
Forms shall be made sufficiently rigid by the use of ties and bracings to prevent any displacement
or sagging between supports. They shall be strong enough to withstand all pressure, ramming and
vibration during and after placing the concrete. Screw jacks or hard wood wedges where required
shall be provided to make up any settlement in the formwork either before or during the placing of
concrete.
The formwork shall take due account of the calculated amount of positive or negative camber so as
to ensure the correct final shape of the structures, having regard to the deformation of false work,
scaffolding or propping and the instantaneous or deferred deformation due to various causes
affecting prestressed structures. Suitable camber shall be provided to horizontal members of
structures, especially in long spans to counteract the effects of deflection. The formwork shall be so
fixed as to provide for such camber.
The formwork shall be coated with an approved release agent that will effectively prevent sticking
and will not stain the concrete surface. Lubricating (machine oils) shall be prohibited for use as
coating.

B-11.12.5 Formed surface & finish

The formwork shall be lined with material approved by the Engineer-in-Charge so as to provide a
smooth finish of uniform texture and appearance. This material shall have no stain on the concrete
and so fixed to its backing as not to impact any blemishes. It shall be of same type and obtained
from only one source throughout for the construction of any structure. The contractor shall make
good any imperfections in the resulting finish as required by the Engineer-in-Charge. Internal ties
and embedded metal parts shall be subject to the approval of the Engineer-in-Charge.

B-11.12.6 Precautions
(a) Special measures in the design of formwork shall be taken to ensure that it does not hinder the
shrinkage of concrete. The soffit of the formwork shall be so designed as to ensure that the
formwork does not restrain the shortening and/or hogging of beams during Pre-stressing. The forms
may be removed at the earliest opportunity subject to the minimum time for removal of forms with
props retained in position.
(b) Where necessary, formwork shall be so arranged that the soffit form, properly supported on props
only can be retained in position for such period as may be required by maturing condition.

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(c) Any cut-outs or openings provided by any structural member to facilitate erection of formwork shall
be closed with the same grade of concrete as the adjoining structure immediately after removal of
formwork ensuring watertight joints.
(d) Provisions shall be made for safe access on, to and about the formwork at the levels as required.
(e) Water used for curing should not be allowed to stagnate near the base plates supporting the staging
and should be properly drained.

B-11.12.7 Preparation of formwork before concreting

The inside surfaces of forms shall, except in the case of permanent form work or where otherwise
agreed to by the Engineer-in-Charge be coated with a release agent supplied by the approved
manufacturer or of an approved material to prevent adhesion of concrete to the formwork. Release
agents shall be applied strictly in accordance with the manufacturer’s instructions and shall not be
allowed to come into contact with any reinforcement or Pre-stressing tendons and anchorages.
Different release agents shall not be used in formwork for exposed concrete.
Before re-use of forms, the following actions shall be taken:
(a) The contact surfaces of the forms shall be cleaned carefully and dried before applying a release
agent.
(b) It should be ensured that the release agent is appropriate to the surface to be coated. The same type
and make of release agent shall be used throughout on similar formwork materials and different
types should not be mixed.
(c) The form surfaces shall be evenly and thinly coated with release agent. The vertical surfaces shall be
treated before horizontal surface and any excess wiped out.
(d) The release agent shall not come in contact with reinforcement or the hardened concrete.
(e) All forms shall be thoroughly cleaned immediately before concreting.
The Contractor shall give the Engineer-in-Charge due notice before placing any concrete in the
forms of to permit him to inspect and approve the formwork, but such inspection shall not relieve
the Contractor of his responsibility for safety of formwork, men , machinery, materials and finish or
tolerances of concrete.

B-11.12.8 Removal of formwork

The scheme for removal of formwork (i.e., de-shuttering and de-centering) shall be planned in
advance and furnished to the Engineer-in-Charge for scrutiny and approval. No formwork or any
part thereof shall be removed without prior approval of the Engineer-in-Charge.
The formwork shall be so removed as not to cause any damage to concrete. Centering shall be
gradually and uniformly lowered in such a manner as to permit the concrete to take stresses due to
its own weight uniformly and gradually to avoid any shock or vibration.
Where not specifically approved, the time of removal of formwork (when ordinary Portland cement
is used without any admixtures at an ambient temperature exceeding 100 C) shall be as under:

(a) Walls, piers, abutments, columns & : 12 to 48 hours as may be decided

vertical faces of structural members by the Engineer in charge.
(b) Soffits of slab with props left under. : 3 days
(c) Props under slab : 14 days
(d) Soffits of girders with props left under. : 7 days
(e) Props under girders : 21 days

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Where there are re-entrant angles in the concrete sections, the formwork should be removed at
these sections as soon as possible after the concrete has set, in order to avoid cracking due to
shrinkage of concrete

B-11.12.9 Re-use of formwork

When formwork is dismantled, its individual components shall be examined for damage and
damaged pieces shall be removed for rectification. Such examination shall always be carried out
before being used again. Before re-use all components shall be cleaned of deposits of soil, concrete
or other unwanted materials. Threaded parts shall be oiled after cleaning.
All bent steel props shall be straightened before re-use. The maximum deviation from straightness
is 1/600 of the length. The maximum permissible axial loads in used props shall be suitably reduced
depending upon their condition. The condition of the timber components, plywood and steel
shuttering plates shall be examined closely for distortion and other defects before re-use.

B-11.12.10 Measurements for payment

The measurement of formwork shall be taken in square meters of the surface area of concrete
which is in contact with the formwork.

B-11.13 NOMINAL MIX CONCRETE

Requirements for nominal mix concrete unless otherwise specified, shall be as detailed in Table B
11.13-1:
Table B 11.13 -1: PROPORTIONS OF NOMINAL MIX CONCRETE

Total Quantity of dry aggregate by mass per 50 kg of

Concrete Proportion of Fine to Coarse
cement to be taken as the sum of individual masses of
Grade Aggregate (by mass)
Fine and Coarse Aggregates (Kg)
M15 350
Generally 1:2, subject to upper limit 1:1½
M20 250 & lower limit of 1: 2½

Cement packed in bag shall be worked out taking as 50 kg. of cement which is 0.035 m3 in volume.
While measuring aggregate by volume, shaking, ramming or hammering shall not be done.
Proportioning of sand shall be as per its dry volume and in case it is damp, allowance for “Bulking”
shall be made as per IS:2386 (Part III).

B-11.14 STRUCTURAL CONCRETE

B-11.14.1 General
The lowest grades of concrete in bridges and corresponding minimum cement contents and water-
cement ratios shall be maintained as indicated in Table B 11.14-1 & B 11.14-2.
The cement content shall be as low as possible but not less than the quantities specified above. In
no case shall it exceed 540 kg/m3.
Concrete used in any component or structure shall be specified by designation along with
prescribed method of design of mix i.e., “Design Mix” or “Nominal Mix”. For all items of concrete,
only “Design Mix” shall be used, except where “Nominal Mix” concrete is permitted as per
drawing or by the Engineer-in-Charge. “Nominal Mix” may be permitted for minor bridges and

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culverts or other incidental construction where strength requirements are upto M 20 only. “Nominal
Mix” may also be permitted for non-structural concrete or for screed below open foundation.
If the Contractor so elects, the Engineer-in-Charge may permit the use of higher grade concrete
than that specified on the drawing, in which event the higher grade concrete shall meet the
specifications applicable thereto without additional compensation.
Table B 11.14-1: REQUIREMENT OF CONCRETE IN PRESTRESSED CONCRETE BRIDGES
(INDIVIDUAL SPAN > 30 m) OR BRIDGES BUILT WITH INNOVATIVE
DESIGN / CONSTRUCTION
Minimum cement content Max. water cement ratio for Minimum grade of concrete
Structural
for all exposure conditions exposure condition: for exposure condition:
Member
(kg/m3) Normal Severe Normal Severe
PCC Members 360 0.45 0.45 M-25 M-30
RCC Members 400 0.45 0.40 M-35 M-40
PSC Members 400 0.40 0.40 M-35 M-40
Table B 11.14-2: REQUIREMENT OF CONCRETE BRIDGES & CULVERTS OTHER THAN AS
SPECIFIED IN TABLE B 11.14-1 & OTHER INCIDENTAL CONSTRUCTION
Minimum cement content
Max. water cement ratio for Minimum grade of concrete
Structural for all exposure conditions
exposure condition: for exposure condition:
Member (kg/m3)
Normal Severe Normal Severe Normal Severe
PCC Members 250 310 0.50 0.45 M-15 M-20
RCC Members 310 400 0.45 0.40 M-20 M-25
Notes:
i. The minimum cement content is based on 20 mm aggregate (nominal max. size). For 40 mm and larger size
aggregates, it may be reduced suitably but the reduction shall not be more than 10%.
ii. For underwater concreting, the cement content shall be increased by 10%.

B-11.14.2 Proportioning of Concrete

Prior to the start of construction, the Contractor shall design the mix in case of “Design Mix
Concrete” or propose nominal mix in case of “Nominal Mix Concrete”, and submit to the Engineer-
in-Charge for approval, the proportions of materials, including admixtures to be used. Water
reducing admixtures (including plasticisers or super-plasticisers) may be used at the Contractor’s
option, subject to the approval of the Engineer-in-Charge. Other types of admixtures shall be
prohibited, unless specifically permitted by the Engineer-in-Charge.

B-11.14.3 Requirements of Consistency

The mix shall have the consistency which will allow proper placement and consolidation of the
required position. Every attempt shall be made to obtain uniform consistency.
The optimum consistency for various types of structures shall be as indicated in Table B 11.14-3, or
as directed by the Engineer-in-Charge. The slump of concrete shall be checked as per IS: 516.

B-11.14.4 Requirements for Designed Mixes

(a) Target means strength
The target mean strength of specimen shall exceed the specified characteristics compressive
strength by at least the “current margin”.
i) The current margin for a concrete mix shall be determined by the Contractor and shall be taken
as 1.64 times the standard deviation of sample test results taken from at least 40 separate
batches of concrete of nominally similar proportions produced at site by the same plant
under similar supervision, over a period exceeding 5 days, but not exceeding 6 months.

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ii) Where there is sufficient data to satisfy the above, the current margin for the initial design
mix shall be taken as given in Table B 11.14-4.
The initial current margin given in the table above shall be used till sufficient data is available to
determine the current margin as per Sub-Clause (i) above.
(b) Trial mixes
The Contractor shall give notice to enable the Engineer-in-Charge to be present at the making of
trial mixes and preliminary testing of the cubes. The Contractor shall prepare trial mixes using
samples of approved materials typical of those he proposes to use in the works, for all grades to the
Engineer-in-Charge’s satisfaction prior to the commencement of concreting. The initial trial mixes
shall generally be carried out in an established laboratory approved by the Engineer-in-Charge. In
exceptional cases, the Engineer-in-Charge may permit the initial trial mixes to be prepared at the
site laboratory of the Contractor. In all cases complete testing of materials forming the constituents
of proposed Design Mix shall have been carried out prior to making trial mixes.
Test cubes shall be taken from trial mixes as follows. For each mix, a set of six cubes shall be made
from each of these consecutive batches. Three cubes from each set of six shall be tested at an age of
28 days and three at an earlier age approved by the Engineer-in-Charges. The cubes shall be made,
cured, stored, transported and tested in accordance with these specifications. The average strength
of the nine cubes at 28 days shall exceed the specified characteristic strength by the current margin
minus 3.5 MPa.
Table B 11.14-3: CONSISTANCIES OF CONDRETE FOR VARIOUS STRUCTURAL
COMPONENTS
Structural component Slump (mm)
(a) Structures with exposed inclined surfaces requiring low slump concrete to allow proper 25
compaction.

(b) Plain cement concrete. 25

(c) RCC structures with widely spaced reinforcements; e.g., solid columns, piers, abutments, 40 - 50
footings, well steining.

(d) RCC structures with fair degree of congestion of reinforcement; e.g. pier and abutment caps, 50 - 75
box culverts, well curb, well cap, walls with thickness greater than 300 mm.

(e) RCC and PSC structures with highly congested reinforcement e.g. deck slab, girders, box 75 - 125
girders, walls with thickness less than 300 mm.

(f) Underwater concreting through tremie e.g. bottom plug, cast-in-situ piling. 100 - 200

Table B 11.14-4: CURRENT MARGINS & TARGET MEAN STRENGTHS OF DIFFERENT

CONCRETE GRADES
Current Margin Target Mean Strength
Concrete Grade
(MPa) (MPa)
M 15 10 25
M 20 10 30
M 25 11 36
M 30 12 42
M 35 12 47
M 40 12 52
M 45 13 58
M 50 13 63
M 55 14 69

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B-11.14.5 Control of Strength of Design Mixes
(a) Adjustment to Mix Proportions
Adjustments to mix proportions arrived at in the trial mixes shall be made subject to the Engineer-in-
Charge’s approval, in order to minimize the variability of strength and to maintain the target mean strength.
Such adjustments shall not be taken to imply any change in the current margin.
(b) Change of Current Margin
When required by the Engineer-in-Charge, the Contractor shall recalculate the current margin in
accordance with Clause 11.4.2.1. The recalculated value shall be adopted as directed by the
Engineer-in-Charge, and it shall become the current margin for concrete produced subsequently.
(c) Additional Trial Mixes
During production, the Contractor shall carry out trial mixes and tests, if required by the Engineer-
in-Charge, before substantial changes are made in the material or in the proportions of the materials
to be used, except when adjustments to the mix proportions are carried out in accordance with Sub-
Clause (a) above.

B-11.14.6 Suitability of Proposed Mix Proportions

The Contractor shall submit the following information for the Engineer-in-Charge’s approval:
a) Nature and source of each material
b) Quantities of each material per cubic meter of fully compacted concrete.
c) Either of the following :
i. Appropriate existing data as evidence of satisfactory previous performance for the target mean
strength, current margin, consistency and water/cement ratio and any other additional
requirement(s) as specified.
ii. Full details of tests on trial mixes.
d) Statement giving the proposed mix proportions for nominal mix concrete.
Any change in the source of material or in the mix proportions shall be subject to the prior approval
of the Engineer-in-Charge.

B-11.14.7 Size of Coarse Aggregate

The size (maximum nominal) of coarse aggregates for concrete to be used in various components
shall be given in Table B 11.14-1
Table B 11.14-1: Maximum Nominal sizes of coarse aggregates
Maximum Nominal Size of Coarse Aggregate
Components
(mm)
i) RCC well curb 20

ii) RCC/PCC well steining 40

iii) Well cap or Pile cap, Solid type piers & abutments 40

iv) RCC work in girders, slabs, wearing coat, kerb, approach 20

slab, hollow piers & abutments, pier/abutment caps, piles.

v) PSC work. 20

vi) Any other item As specified by Engineer-in-Charge

Maximum nominal size of aggregates shall also be restricted to the smaller of the following values:
a) 10 mm less than the minimum lateral clear distance between main reinforcements.

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b) 10 mm less than the minimum clear cover to the reinforcements.

The proportions of the various individual size of aggregates shall be so adjusted that the grading
produces densest mix and the grading curve corresponds to the maximum nominal size adopted for
the concrete mix.

B-11.14.8 Mixing of Concrete

Concrete shall be mixed either in a concrete mixer or in a batching and mixing plant, as per
specifications. Hand mixing shall not be permitted. The mixer or the plant shall be at an approved
location considering the properties of the mixes and the transportation arrangements available with
the Contractor. The Engineer-in-Charge shall approve the mixer or the plant.
Mixing shall be continued until materials are uniformly distributed and a uniform colour of the
entire mass is obtained and each individual particle of the coarse aggregates shows complete
coating of mortar containing its proportionate amount of cement. In no case shall the mixing be
done for less than two minutes after all ingredients have been put into the mixture.
Mixers that have been out of use for more than 30 minutes shall be thoroughly cleaned before
putting in a new batch. Unless otherwise agreed to by the Engineer-in-Charge, the first batch of the
concrete from the mixer shall contain only 2/3rd of the normal quantity of coarse aggregate. Mixing
plant shall be thoroughly cleaned before changing one type of cement to another.
In exceptional case when the hand-mixing is permitted by the Engineer-in-Charge for small jobs or
certain other reasons it shall be done on a smooth water tight platform, large enough to allow
efficient turning over of the ingredients of concrete before and after adding water. Mixing platform
shall be so arranged that no foreign material shall be mixed with concrete nor does the mixing
water flow out. Cement in required number of bags shall be placed in a uniform layer on top of the
measured quantity of fine aggregate, which shall also be spread in a layer of uniform thickness on
the mixing platform.
Dry sand and cement shall then be mixed thoroughly by turning over to get a mixture of uniform
colour. Enough water shall then be added gradually through a nose and be mass turned over until a
mortar of required consistency is obtained. Measured quantity of coarse aggregate, shall then be
placed on the mixing platform and wetted and the mortar added and the entire mass turned and
returned until all particles of coarse aggregate are fully covered with mortar and mixture obtained is
of uniform colour and required consistency.

B-11.14.9 Transporting, placing and compaction of concrete

The Engineer-in-Charge shall approve the method of transporting and placing concrete. Concrete
shall be transported and placed as near as practicable to its final position, so that no contamination,
segregation or loss of constituent materials takes place. Concrete shall not be freely dropped into
place from a height exceeding 1.5 meters.
When concrete is conveyed by chute, the plant shall be of such size and design as to ensure
practically continuous flow. Slope of the chute shall be so adjusted that the concrete flows without
the use of excessive quantity of water and without any segregation of its ingredients. The delivery
end of the chute shall be as close as possible to the point of deposit. The chute shall be thoroughly
flushed with water before and after each working period and the water used for this purpose shall
be discharged outside the formwork.
All formwork and reinforcement contained in it shall be cleaned and made free from standing
water, dust, snow or ice immediately before placing of concrete.

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No concrete shall be placed in any part of the structure until the approval of the Engineer-in-Charge
has been obtained.
If concreting is not started within 24 hours of the approval being given, it shall have to be obtained
again from the Engineer-in-Charge. Concreting then shall proceed continuously over the area
between the construction joints. Fresh concrete shall not be placed against concrete which has been
in position for more than 30 minutes unless a proper construction joint is formed.
Concrete shall be compacted to its final position within 30 minutes of its discharge from the mixer,
unless carried in properly designated agitators, operating continuously, when this time shall be
within 1 hour of the addition of cement to the mix and within 30 minutes of its discharge from the
agitator. It may be necessary to add retarding admixtures to concrete if trials show that the periods
indicated above are unacceptable. In all such matters, the Engineer-in-Charge’s decision shall be
final.
Concrete shall be thoroughly compacted by vibration or other means during placing and worked
around the reinforcement, tendons or duct formers, embedded fixtures and into corners of
formwork to produce a dense homogeneous void-free mass having the required surface finish.
When vibrators are used, vibrations shall be done continuously during the placing of each batch of
concrete until the expulsion of air has practically ceased and in a manner that does not promote
segregation. Over vibration shall be avoided to minimize the risk of forming a weak surface layer.
When external vibrators are used, the design of the formwork and disposition of vibrator shall be
such as to ensure efficient compaction and to avoid surface blemishes.
Vibrations shall not applied through reinforcement and where vibrators of immersion type are used,
contact with reinforcement and all inserts like ducts, etc shall be avoided. The internal vibrators
shall be inserted in an orderly manner and the distance between insertions should be about one and
a half times the radius of the area visibly affected by vibration.

B-11.14.10 Construction joints

Construction joints shall be avoided as far as possible and in no case the locations of such joints
shall be changed or increased from those shown in the drawings, except with express approval of
the Engineer-in-Charge. The joints shall be provided in a direction perpendicular to the member
axis.

B-11.14.11 Concreting under water

When it is necessary to deposit concrete under water, the methods, equipment, materials and
proportions of the mix to be used shall be approved by the Engineer-in-Charge before any work is
started. Concrete shall contain 10% more cement than that required for the same mix placed in the
dry.
Concrete shall not be placed in water having a temperature below 50C. the temperature of concrete,
when deposited, shall not be less than 160 C, nor more than 400C.
Coffer dams or forms shall be sufficiently tight to ensure still water conditions, if practicable, and
in any case to reduce the flow of water to less than 3m/sec through the space into which concrete is
to be deposited. Coffer dams or forms in still water shall be sufficiently tight to prevent loss of
mortar through the joints in the walls.
All underwater concrete shall be carried out by tremie method only, using tremie of appropriate
diameter, the number and spacing of the tremies should be worked out to ensure proper concreting.
The tremie concreting when started should continue without interruption for the full height of the

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member being concreted. The concrete production and placement equipment should be sufficient to
enable the underwater concrete to be completed uninterrupted within the stipulated time.
The top section of the tremie shall have a hopper large enough to hold one full batch of the mix or
the entire contents of the transporting bucket as the case may be. The tremie pipe shall be not less
than 200 mm in diameter and shall be large enough to allow a free flow of concrete and strong
enough to withstand the external pressure of the water in which it is suspended, even if a partial
vacuum develops inside the pipe. Preferably, flanged steel pipe of adequate strength for the job
shall be used. A separate lifting device shall be provided for each tremie pipe with its hopper at the
upper end. Unless the lower end of pipe is equipped with an approved automatic check valve, the
upper end of the pipe shall be plugged with wadding of gunny stacking or other approved material
before delivering the concrete to the tremie pipe through the hopper, so that when the concrete is
forced down from the hopper to the pipe it will force the plug (and along with it any water in the
pipe) down the pipe and out of the bottom and, thus establishing a continuous stream of concrete. It
will be necessary to raise slowly the tremie in order to allow a uniform flow of concrete, but it shall
not be emptied so that water enters above the concrete in the pipe. At all times after the placing of
concrete is started and until all the required quantity has been placed, the lower end of tremie pipe
shall be kept below the top surface of the plastic concrete. This will cause of concrete to build up
form below instead of flowing out over the surface, and thus avoid formation of layer s of laitance.
If the charge in the tremie is lost while depositing, the tremie shall be raised above the concrete
surface and unless sealed by a check valve it shall be re-plugged at the top end, as at the
beginnings, before re-filling for depositing further concrete.

B-11.14.12 Adverse weather conditions

(a) Cold Weather Concreting
Where concrete is to be deposited at or near freezing temperatures, precautions shall be taken to
ensure that at the time of placing it has a temperature of not less than 5ºC and that temperature of
concrete shall be maintained above 4oC, until it has thoroughly hardened. When necessary, concrete
ingredients shall be heated before mixing but cement shall not be heated artificially. In general, the
temperature of aggregates or water shall not exceed 65º C. No frozen materials or materials
containing ice shall be used. All concrete damaged by frost shall be removed.
(b) Hot Weather Concreting
When depositing concrete in very hot weather, precautions shall be taken so that the temperature of
wet concrete does not exceed 40ºC while placing. This shall be achieved by stacking aggregate
under the shade and keeping them moist, using cold water, reducing the time between mixing and
placing to the minimum, cooling form work by sprinkling water, starting curing before concrete
dries out and restricting concreting, as far as possible, to early mornings and late evenings. When
ice is used to cool mixing water, it will be considered a part of the water in design mix. Under no
circumstances shall the mixing operation be considered complete until all ice in the mixing drum
has melted.
The Contractor will be required to state his methodology for the Engineer-in-Charge’s approval
when temperatures of concrete are likely to exceed 400 C during the work.

B-11.14.13 Protection and curing of concrete

Concreting operations shall not commence until adequate arrangements for concrete curing have
been made by the Contractor.
Curing and protection of concrete shall start immediately after compaction of the concrete to
protect it form:-

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(a) Pre-mature drying out, particularly by solar radiation and wind.
(b) High internal thermal gradients.
(c) Leaching out by rain and flowing water.
(d) Rapid Curing during the first few days after placing.
(e) Low temperature or frost.
(f) Vibration or impact which may disrupt the concrete and interfere with its bond to the reinforcement.
When members are of considerable size and length, with high cement content, accelerated curing
methods may be applied, as approved by the Engineer-in-Charge.

B-11.14.14 Water Curing of Concrete

Sea water shall not be used for curing. Sea water shall not come into contact with concrete
members unless it has attained adequate strength.
Exposed surfaces of concrete shall be kept continuously in a damp or wet condition by ponding or
by covering with a layer of sacks, canvas, hessian or similar materials and shall be kept constantly
wet for a period of not less than fourteen days from the date of placing of concrete.
Masonry work over foundation concrete may be started after 48 hours of it’s laying but the curing
of concrete shall be continued for a minimum period of 14 days.

B-11.14.15 Curing Compounds

Curing compounds shall only be permitted in special circumstances and will require specific
approval of the Engineer-in-Charge. Curing compounds shall not be used on any surface which
requires further finishing to be applied. All construction joints shall be moist, cured and no curing
compound will be permitted in locations where concrete surfaces are required to be bonded
together.
Curing compounds shall be continuously agitated during use. All concrete cured by this method
shall receive two applications of the curing compound. The first coat shall be applied immediately
after acceptance of concrete finish. If the surface is dry, the concrete shall be saturated with water
and curing compounds applied as soon as the surface film of water disappears. The second
application shall be made after the first application has set. Placement in more than two coats may
be required to prevent streaking.

B-11.14.16 Finishing
Immediately after the removal of forms, exposed bars or bolts, if any, shall be cut inside the
concrete member to a depth of at least 50 mm below the surface of concrete and the resulting holes
filled with cement mortar. All fins caused by form joints, all cavities produced by the removal of
form ties and all other holes and depressions, honeycomb spots, broken edges or corners, and other
defects, shall be thoroughly cleaned, saturated with water, and carefully pointed and rendered true
with mortar of cement and fine aggregate mix in the proportions used in the grade of concrete that
is being finished and of as dry a consistency as is possible to use. Considerable pressure shall be
applied in filling and pointing to ensure thorough filling in all voids. Surfaces which have been
pointed shall be kept moist for a period of 24 hours. Special pre-packaged proprietary mortars shall
be used where appropriate or where specified in the drawing.
All construction and expansion joints in the completed work shall be left carefully tooled and free
from any mortar and concrete. Expansion joint filler shall be left exposed for its full length with
clean and true edges.

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Immediately on removal of forms, the concrete work shall be examined by the Engineer-in-Charge
before any defects are made good.
a) The work that has sagged or contains honeycombing to an extent detrimental to structural safety or
architectural appearance shall be rejected.
b) Surface defect of a minor nature may be accepted. On acceptance of such work by the Engineer-in-
Charge, the same shall be rectified as directed by the Engineer-in-Charge.

B-11.14.17 Tests and standards of acceptance

Random sampling and lot by lot acceptance inspection shall be made for the 28 days cube strength
of concrete.
Concrete under acceptance shall be notionally divided into lots for the purpose of sampling, before
commencement of work. The delimitation of lots hall be determined by the following:
(i) No individual lot shall be more than 30 m3 in volume.
(ii) At least one cube forming an item of the sample representing the lot shall be taken from
concrete of the same grade and mix proportions cast in any day.
(iii) Different grades of mixes of concrete shall be divided into separate lots.
(iv) Concrete of a lot shall be used in the same identifiable unit of the bridge.

B-11.14.18 Sampling and Testing

Concrete for making 3 test cubes shall be taken from a batch of concrete at point of discharge from the mixer
according to procedures laid down in IS: 1199.
A random sampling procedure to ensure that each of the concrete batches forming the lot under acceptance
inspection has equal chance of being down for taking cubes shall be adopted.
150 mm. cubes shall be made, cured and tested at 28 days age for compressive strength conforming to IS:
516. The 28-day test strength result for each cube shall form an item of the sample.

B-11.14.19 Test Specimen & Sample Strength

Three test specimens shall be made from each sample for testing at 28 days. Additional cubes may
be required for various purposes such as to determine the strength of concrete at 7 days or any other
purpose.
The test strength of the sample shall be the average of the strength of 3 cubes. The individual
variation should not be more than ±15% of the average.

B-11.14.20 Frequency
The minimum frequency of sampling of concrete of each grade shall be in accordance with the
Table B 11.14-2, subjected to at least one sample from each shift of work.:

B-11.14.21 Acceptance Criteria

Compressive Strength
When both the following conditions are met, the concrete complies with the specified compressive
strength:
a) The mean strength from any group of 4 consecutive samples should exceed the specified
characteristics compressive strength.
b) Strength of any sample is not less than the specified characteristics compressive strength minus 3
MPa.

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The quantity of concrete represented by the test results include the batches from which the first and
last samples were taken, together with all intervening batches.
Table B 11.14-2: FREQUENCY OF SAMPLING OF CONCRETE
Quantity of Concrete in work No. of Samples
(m3)
1-5 1
6-15 2
16-30 3
31-50 4
51 and above. 4 plus one additional samples for each additional 50 m3 or part
thereof.

If the concrete is deemed not to comply with the requirement as stated above and other tests the
Engineer-in-Charge may at his discretion direct either the portion of the concrete certified by him
as so deficient in strength and to be removed from the structure and be replaced by concrete of
specified strength and the Contractor shall in that case has to carry out the direction at his own cost
irrespective of the amount of loss, inconvenience and difficulties involved. The Engineer-in-Charge
may allow to retain the same from practical or other consideration on due investigation of
structural condition of the affected parts. In that case the Contractor shall have to bear the costs of
investigation thereof. If the concrete be so allowed to stand the Contractor will have also to accept
deduction in the rate of concrete so affected which may be fixed by the Superintending Engineer
concerned and the decision of the Superintending Engineer shall be final and binding to the part of
the Contractor.
When concrete of a specified work is found to be acceptable to the Engineer-in-Charge but the
desired compressive strength has not been achieved a reduction of the rate may be applied as under:

(Design strength – Observed strength)

Percent (%) reduction = x 100
Design strength
B-11.14.22 Density of Fresh & Hardened Concrete
Where minimum density of fresh concrete is specified, the mean of any 4 consecutive samples shall
not be less than the specified value and any individual sample result shall not be less than 97.5 % of
the specified value.

B-11.14.23 Measurement for payment

Structural concrete shall be measured in cubic meters. In reinforced or prestressed concrete, the
volume occupied by reinforcement or Pre-stressing cables and sheathing shall not be deducted.

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B-11.15 PRESTRESSED CONCRETE WORK

Structural concrete containing prestressed steel reinforcement to introduce pre-compression is
termed as prestressed concrete.
The work shall be carried out in accordance with the drawing and these specifications or as
approved by the Engineer.
Concrete and un-tensioned steel for the construction of prestressed concrete members shall conform
to the requirements of IRC Specification.
B-11.15.1 Materials
All materials shall conform to Section B-11.1 to B-11.11
B-11.15.2 Sheathing
The sheathing ducts shall be of the spiral corrugated type. Unless otherwise specified, the material
shall be Cold Rolled Cold Annealed (CRCA) Mild Steel conforming to IS: 513 intended for
mechanical treatment and surface refining but not for quench hardening or tempering.
The material shall normally be bright finished. However, where specified as in case of use in
aggressive environment, galvanized or lead-coated mild steel strips shall be used.
The thickness of sheathing shall be as shown on the drawing, but shall not be less than 0.3 mm., 0.4
mm. and 0.5 mm. for sheathing ducts having internal diameter of 50 mm., 75 mm. and 90 mm.
respectively. For bigger diameters of ducts, thickness of sheathings shall be based on the
recommendations of prestressing system supplier, or as directed by the Engineer-in-Charge.
The sheathing shall conform to the requirement as per tests specified in Specifications for Road &
Bridge Works (MoRTH), 4th revision.
For major projects, the sheathing ducts should preferably be manufactured at the project site
utilizing appropriate machines. With such an arrangement, long lengths of sheathing ducts may be
used with consequent reduction in the number of joints and couplers. Where sheathing duct joints
are unavoidable, such joints shall be made slurry tight by the use of corrugated threaded sleeve
couplers which may be tightly screwed onto the outer side of the sheathing ducts.
The length of the coupler should not be less than 150 mm. but should be increased upto 200 mm.
wherever practicable. The joints between the ends of the coupler and the duct shall be sealed with
adhesive sealing tape to prevent penetration of cement slurry during concreting. The couplers of
adjacent ducts should be staggered wherever practicable. As far as possible, couplers should not be
located in curved zones. The corrugated sleeve couplers are being conveniently manufactured using
the sheath making machine with the next higher size of die set.
The internal area of the sheathing duct shall be in accordance with the recommendations of the
system manufacturer and shall be about three times the area of the tendons. In case of 6T13, 12T13
and 19T13 sizes of tendons comprising 12/13 mm. dia strands, the inner diameter of the sheathing
shall not be less than 50 mm, 75 mm. and 90 mm. respectively or those shown in the drawing,
which ever is greater.
Where Pre-stressing tendons are required to be threaded after concreting the diameter of sheathing
shall be about 5 mm. larger than that required as above.
In severe environment, cables shall be threaded after concreting. In such cases a temporary tendon
shall be inserted in the sheathing or the sheathing shall be stiffened by other suitable method during
concreting.

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B-11.15.3 Anchorages
Anchorages shall be procured from authorised manufacturers only. Anchorages shall conform to
BS: 4447. Test certificates from a laboratory fully equipped to carry out the tests shall be furnished
to the Engineer. Such test certificates shall not be more than 12 months old at the time of making
the proposal for adoption of a particular system for the project.
No damaged anchorages shall be used. Steel parts shall be protected from corrosion at all times.
Threaded parts shall be protected by greased wrappings and tapped holes shall be protected by
suitable plugs until used. The anchorage components shall be kept free from mortar and loose rust
and any other deleterious coating.
Swages of pre-stressing strand and button-heads of Pre-stressing wire, where provided shall
develop strength of at least 95 per cent of the specified breaking load of the strand or wire as the
case may be. Where swaging / button-heading is envisaged, the contractor shall furnish details of
his methodology and obtain approval of the Engineer-in-Charge, prior to his taking up the work.
Un-tensioned steel reinforcements, around anchorages shall conform to the details of Pre-stressing
system and as shown on the drawing.
B-11.15.4 Testing of pre-stressing steel and anchorages
All materials specified for testing shall be furnished free of cost and shall be delivered in time for
tests to be made well in advance of anticipated time of use.
All wire, strand or bars to be shipped to the site shall be assigned a lot number and tagged for
identification purposes. Anchorage assemblies to be shipped shall be like-wise identified.
All samples submitted shall be representative of the lot to be furnished and in the case of wire or
strand, shall be taken from the same master roll. The contractor shall furnish samples of at least 5.0
m length selected from each lot for testing. Also, two anchorage assemblies, complete with
distribution plates of each size or types to be used, shall be furnished along with short lengths of
strands as required.
B-11.15.5 Workmanship
(a) Cleaning
Tendons shall be free from loose rust, oil, grease, tar, paint, mud or any other deleterious substance.
Cleaning of the steel may be carried out by immersion in suitable solvent solutions wire brushing or
passing through a pressure box containing carborundum powder. However, the tendons shall not be
brought to a polished condition.
(b) Straightening
High tensile steel wire and strand shall be supplied in coils of sufficiently large diameter such that
tendons shall retain their physical properties and shall be straight as it unwinds from the coil.
Tendons of any type that are damaged, kinked or bent shall not be used.
The packing of Pre-stressing wire / strand shall be removed only just prior to making of cable for
placement. Suitable stands shall be provided to facilitate uncoiling of wires / strands without
damage to steel. Care shall be taken to avoid the possibility of steel coming into contact with the
ground.
(c) Positioning
(i) Post-Tensioning
Pre-stressing tendons shall be accurately located and maintained in position, both vertically and
horizontally, as per drawings.

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Tendons shall be so arranged that they have a smooth profile without sudden bends or kinks.
The positioning of prestressed cables shall be such as to facilitate easy placement and vibration of
concrete in between the tendons. High capacity tendon shall be used to reduce the number of cables
thereby eliminating the necessity of grouping. The selected profiles of the tendons shall be such
that their anchorages are not located in the top deck surface. Where two or more rows of cables
have to be used, the cables shall be vertically in line to enable easy flow of concrete. The clear
vertical and horizontal distances between any two cables shall in no case be less than 100 mm.
anywhere along the length of the superstructure. Where precast segments are used, the clear
distance shall be at least 150 mm.
Sheathing shall be placed in correct position and profile by providing suitable ladders and spacers.
Such ladders may be provided at intervals of approximately 1.0 m. Sheathing shall be tied rigidly
with such ladders / spacer bars so that they do not get disturbed during concreting.
The method of supporting and fixing shall be such that profile of cables is not disturbed during
vibrations, by pressure of wet concrete, by workmen or by construction traffic.
Sheathing in which the permanent tendon will not be in place during concreting shall have a
temporary tendon inserted or shall be stiffened by some other method to the approval of the
Engineer. The temporary tendon shall be pulled out before threading the permanent tendon into
place by a special threading machine or other contrivance.
Where possible, tendons shall not be placed until immediately prior to stressing. Tendons shall be
handled with care to avoid damage or contamination, to either the tendon or the sheathing. Any
tendon damaged or contaminated shall be cleaned or replaced.
(ii) Pre-Tensioning
Pre-stressing steel shall be accurately located and maintained in position, both vertically and
horizontally, as per drawings.
Each anchorage device shall be set square to the line of action of the corresponding Pre-stressing
tendon and shall be positioned securely to prevent movement during concreting.
The anchorage devices shall be cleaned to the satisfaction of the Engineer-in-Charge prior to the
placing of concrete. After concreting, any mortar or concrete which adheres to bearing or wedging
surfaces shall be removed immediately.
(iii) Cutting
Cutting and trimming of wires or strands shall be done by suitable mechanical or flame cutters.
When a flame cutter is used, care shall be taken to ensure that the flame does not come in contact
with other stressed steel. The location of flame cutting of wire or strand shall be kept beyond 75
mm. of where the tendon will be gripped by the anchorage or jacks.
In post-tensioning the ends of Pre-stressing steel projecting beyond the anchorages, shall be cut
after the grout has set.
B-11.15.6 Protection of Pre-stressing Steel
Pre-stressing steel shall be continuously protected against corrosion, until grouted. The corrosion
protector shall have no deleterious effect on the steel or concrete or on the bond strength of steel to
concrete. Grouting shall conform to these specifications or as directed by the Engineer-in-Charge.
In the case of external Pre-stressing, steel shall be encased in suitable polyethylene pipes before
grouting.

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B-11.15.7 Sheathing
The joints of all sheathings shall be water-tight. Special attention shall be paid to the junction at the
anchorage end, where the sheathing must tightly fit on the protruding trumpet end of anchorage and
thereafter sealed preferably with heat shrink tape, to make it water-proof.
The heat-shrink tape is supplied in the form of bandage rolls which can be used for all diameters of
sheathing ducts. The bandage is coated on the underside with heat sensitive adhesive so that after
heating the bandage material shrinks on the sheathing duct and ensures formation of a leak-proof
joint. The heating is effected by means of a soft gas flame.
A sheath making machine should be positioned at the site of work for large projects so that
sheathing can be prepared as and when it is required for construction.
The sheathing and all joints shall be water tight. Any temporary opening in the sheathing shall be
satisfactorily plugged and all joints between sheathing and any other part of the Pre-stressing
system shall be effectively sealed to prevent entry of mortar, dust, water or other deleterious matter.
Sheathing shall be neatly fitted at joints without internal projection or reduction of diameter.
Enlarged portions of the sheathing at couplings or anchorages shall be of sufficient length to
provide for the extension of the tendons.
B-11.15.8 Grout Vents
Grout vents of at least 20 mm. diameter shall be provided at both ends of the sheathing and at all
valleys and crests along its length. Additional vents with plugs shall also be provided along the
length of sheathing such that the spacing of consecutive vents do not exceed 20 m. Each of the
grout vents shall be provided with a plug or similar device capable of withstanding a pressure of 1.0
MPa without the loss of water, air pressure or grout.
B-11.15.9 Anchorages
All bearing surfaces of the anchorages shall be cleaned prior to concreting and tensioning.
Anchor cones, blocks and plates shall be securely positioned and maintained during concreting
such that the centre line of the duct passes axially through the anchorage assembly.
The anchorages shall be recessed from the concrete surface by a minimum cover of 100 mm.
After the Pre-stressing operations are completed and Pre-stressing wires / strands are cut, the
surface shall be painted with two coats of epoxy of suitable formulation having a dry film thickness
of 80 microns per coat and entire recess shall be filled with concrete or non-shrink / pre-packaged
mortar or epoxy concrete.
B-11.15.10 Structural Concrete
Structural concrete and the formwork shall conform to I.R.C. specification.
B-11.15.11 Supervision
All Pre-stressing and grouting operations shall be undertaken by trained personnel only. A
representative of supplier of the Pre-stressing system shall be present during all tensioning and
grouting operations and shall ensure, monitor and certify their correctness.
B-11.15.12 Tensioning equipments
All tensioning equipment shall be procured from authorised manufacturers only and be approved by
the Engineer prior to use. Where hydraulic jacks are used, they shall be power-driven unless
otherwise approved by the Engineer. The tensioning equipment shall satisfy the following
requirements:

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i) The means of attachments of the Pre-stressing steel to the jack or any other tensioning
apparatus shall be safe and secure.
ii) Where two or more wires / strands constitute a tendon, a single multiple stressing jack shall
be used which is capable of tensioning simultaneously all the wires / strands of the tendon.
Suitable facilities for handling and attaching and multiple jack to the tendons shall be
provided.
iii) The tensioning equipment shall be such that it can apply controlled total force gradually on
the concrete without inducing dangerous secondary stresses in steel, anchorage or concrete
and
iv) Means shall be provided for direct measurement of the force by use of dynamometers or
pressure gauges fitted in the hydraulic system itself to determine the pressure in the jacks.
Facilities shall also be provided for the linear measurement of the extension of Pre-stressing
steel to the nearest mm. and of any slip of the gripping devices at transfer.
All dynamo meters and pressure gauges including a master gauge shall be calibrated by an
approved laboratory immediately prior to use and then at intervals not exceeding 3 months and the
true force determined from the calibration curve.
Pressure gauges shall be concentric scale type gauges accurate to within two per cent of their full
capacity. The minimum nominal size of gauge shall be 100 mm. The gauge shall be so selected that
when the tendon is stressed to 75 per cent of its breading load, the gauge is reading between 50 per
cent and 80 per cent of its full capacity. Suitable safety devices shall be fitted to protect pressure
gauges against sudden release of pressure.
Provision shall be made for the attachment of the master gauge to be used as a check whenever
requested for by the Engineer.
B-11.15.13 Post-tensioning
Tensioning force shall be applied in gradual and steady steps and carried out in such a manner that
the applied tensions and elongations can be measured at all times. The sequence of stressing,
applied tensions and elongations shall be in accordance with the approved drawing or as directed by
the Engineer.
It shall be ensured that in no case, the load is applied to the concrete before it attains the strength
specified on the drawing or as stipulated by the Pre-stressing system supplier, whichever is more.
After Pre-stressing steel has been anchored, the force exerted by the tensioning equipment shall be
decreased gradually and steadily so as to avoid shock to the Pre-stressing steel or anchorage.
The tensioning force applied to any tendon shall be determined by direct reading of the pressure
gauges or dynamo-meters and by comparison of the measured elongation with the calculated
elongation. The calculated elongation shall be invariably adjusted with respect to the modulus of
elasticity of steel for the particular lot as given by the manufacturer.
The difference between calculated and observed tension and elongation during Pre-stressing
operations shall be regulated as follows:
a) If the calculated elongation is reached before the specified gauge pressure is obtained, continue
tensioning till attaining the specified gauge pressure, provided the elongation does not exceed
1.05 times the calculated elongation. If 1.05 times the calculated elongation is reached before
the specified gauge pressure is attained, stop stressing and inform the Engineer.

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b) If the calculated elongation has not been reached at the specified gauge pressure, continue
tensioning by intervals of 5 kg/sq.cm. until the calculated elongation is reached provided the
gauge pressure does not exceed 1.05 times the specified gauge pressure.
c) If the elongation at 1.05 times the specified gauge pressure is less than 0.95 time the calculated
elongation, the following measures must be taken in succession, to determine the cause of this
lack of discrepancy :
i) Check the correct functioning of the jack, pump and leads.
ii) De-tension the cable. Slide it in its duct to check that it is not blocked by mortar which
has entered through holes in the sheath. Re-tension the cable if free.
iii) Re-establish the modulus of elasticity of steel for the particular lot from an approved
laboratory.
If the required elongation is still not obtained, further finishing operations such as cutting or
sealing, should not be undertaken without the approval of the Engineer-in-Charge.
When stressing from one end only, the slip at the end remote from the jack shall be accurately
measured and an appropriate allowance made in the measured extension at the jacking end.
A complete record of Pre-stressing operations along with elongation and jack pressure data shall be
maintained in the format of the relevant appendix of Specifications for Road & Bridge Works
(MoRTH), 4th revision. The number of stages of Pre-stressing and grouting shall be reduced to a
minimum, preferably 2 in the case of simply supported girders.
B-11.15.14 Grouting of Pre-stressed tendons
Grouting shall conform to relevant appendix of Specifications for Road & Bridge Works
(MoRTH), 4th revision. A record of grouting operations shall be maintained in the format given in
the book.
B-11.15.15 Safety precautions during tensioning
Care shall be taken during tensioning to ensure the safety of all persons in the vicinity.
Jacks shall be secured in such a manner that they will be held in position, should they lose their grip
on the tendons.
No person shall be allowed to stand behind the jacks or close to the line of the tendons while
tensioning is in progress.
The operations of the jacks and the measurement of the elongation and associated operations shall
be carried out in such a manner and from such a position that the safety of all concerned is ensured.
A safety barrier shall be provided at both ends to prevent any tendon, which might become loose
from recoiling unchecked.
During actual tensioning operation, warning sign shall be displayed at both ends of the tendon.
After Pre-stressing, concrete shall neither be drilled nor any portion cut nor chipped away nor
disturbed, without express approval of the Engineer.
No welding shall be permitted on or near tendons nor shall any heat be applied to tendons. Any
tendon which has been affected by welding, weld spatter or heat shall be rejected.
B-11.15.16 Tolerances
Permissible tolerances for positional deviation of Pre-stressing tendons shall be limited to the
following:
i) Variation from the specified horizontal profile : 5 mm.

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ii) Variation from the specified vertical profile : 5 mm.

iii) Variation from the specified position in member : 5 mm.
iv)
B-11.15.17 Tests and Standards of acceptance
The materials shall be tested in accordance with these Specifications and shall meet the prescribed
criteria. The work shall conform to these Specifications and shall meet the prescribed standards of
acceptance.
B-11.15.18 Measurements for payments
Prestressed concrete shall be measured in cubic meters. The volume occupied by mild steel
reinforcement / HYSD bars, high tensile steel, sheathing and anchorages shall not be deducted.
High tensile (Pre-stressing) steel be paid for separately and its length shall be measured as actually
incorporated in the finished work.

B-11.16 BORED CAST-IN-SITU CONCRETE PILES

The design and construction of bored cast-in-situ concrete piles shall generally be governed by the
recommendations of IS 2911 and IRC: 78-2000 with latest amendments.
The pile formed within the ground by excavating or boring a hole within it with or without the use
of a permanent casing and subsequent filling it with plain or reinforced concrete is termed as a
bored cast-in-situ pile. Cover to main reinforcement in pile shaft shall be not less than 75 mm and
the minimum clear distance between two adjacent main reinforcement shall not be less than 150
mm. A minimum length of one meter of temporary casing shall be inserted in each pile. For marine
situation such piles shall be formed with permanent casing. Boring operation shall generally be
done by rotary or percussion type drilling rigs using direct or reverse mud circulation methods to
bring the cuttings out. Rope operated grabbing tool or Kelly mounted hydraulically operated grab
may also be used. For stabilizing sides of boreholes drilling mud shall be used.
The casing/liner shall be driven open ended with a pile driving hammer capable of achieving
penetration of the liner to the length shown on the drawing or as approved by the Engineer-in-
Charge. Materials inside the casing shall be removed progressively by air lift, grab or percussion
equipment or other approved means.
Where bored cast-in-situ piles are used in soils liable to flow, the bottom of the casing shall be kept
enough in advance of the boring tool to prevent the entry of soil into the casing, thus preventing the
formations of cavities and settlements in the adjoining ground. The water level in the casing should
generally be maintained at the natural ground water level for the same reasons. The joints of the
casing shall be made as tight as possible to minimize inflow of water or leakage of slurry during
concreting.
Prior to the lowering of the reinforcement cage into the pile shaft, the shaft shall be cleaned of all
loose materials. Cover to the reinforcing steel shall be maintained by suitable spacers.
The diameter of the finished pile shall be less than that specified and a continuous record shall be
kept by the Engineer as to the volume of concrete placed in relation to the pile length cast.
Before concreting under water, the bottom of the hole shall be cleaned of drilling mud and all soft
or loose material very carefully. In case a hole is bored with use of drilling mud, concreting shall
not be taken up when the specific gravity of bottom slurry is more than 1.2. The drilling mud
should be maintained at 1.5 m above the ground water level.

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Tremies of 150 to 200 mm diameter shall be used for concreting. The tremie should have uniform
and smooth cross-section inside, and shall be withdrawn slowly ensuring adequate height of
concrete outside the tremie pipe at all stages of withdrawal. Other recommendations for tremie
concreting are:
a) The sides of the borehole have to be stable throughout;
b) The tremie shall be watertight throughout the length and a hopper attached to its head by a
watertight connection;
c) The tremie pipe should be lowered to the bottom of the borehole, allowing ground water or
drilling mud to rise inside it before pouring concrete;
d) The tremie pipe should always be kept full of concrete and should penetrate well into the
concrete in the borehole with adequate margin of safety against accidental withdrawal if the
pipe is surged to discharge the concrete.
Concreting under water may be done either with use of tremie method or by use of an approved
method specially designed to permit under water placement of concrete.
General requirements and precautions for concreting under water are as follows:
a) The concreting of a pile must be completed in one continuous operation. Also, for bored
holes, the finishing of the bore, cleaning of the bore, lowering of reinforcement cage and
concreting of pile for full height must be accomplished in one continuous operation without
any stoppage.
b) The concrete shall be coherent, rich in cement with high slump and restricted water cement
ratio.
c) The tremie pipe will have to be large enough with due regard to the size of aggregates. For
20 mm aggregate the tremie pipe shall be of diameter not less than 150 mm and for larger
aggregates, larger diameter tremie pipes may be necessary.
d) The first charge of concrete should be placed with a sliding plug pushed down the tube ahead
of it to prevent mixing of water and concrete.
e) The tremie pipe should always penetrate well into the concrete with an adequate margin of
safety against accidental withdrawal if the pipe is surged to discharge the concrete.
f) The pile should be concreted wholly by tremie and of method of deposition should not be
changed part way up the pile to prevent the laitance from being entrapped within the pile.
g) All tremie tubes should be thoroughly cleaned after use.
h) For cast-in-situ piles the values regarding grade of concrete, water-cement ratio, and slump
shall be as follows:
Grade of concrete M 35
Minimum cement content 400 kg/m3
Maximum water-cement ratio 0.40
Slump 100 – 130 mm

B-11.17 PILE TESTS

B-11.17.1 General
The bearing capacity of a single pile may be determined from test loading a pile. The load test on a
concrete pile may not be carried out earlier than 28 days from the time of casting of the pile.

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There shall be two categories of tests on piles, namely, initial tests and routine tests. Initial tests
should be carried out on test piles which are not to be incorporated in the work. Routine tests shall
be carried out as a check on working piles. The number of initial and routine tests on piles shall be
as determined by the Engineer-in-Charge depending upon the number of foundations, span length,
and type of superstructure and uncertainties of founding strata. In any case, the initial load tests
shall not be less than 2 in number, while the routine load tests shall not be less than 2 per cent of the
total number of piles in the structure nor less than 2 in number.
The above stipulations hold good for both vertical as well as lateral load tests on pile foundations.
However, both initial and routine tests may be suitably increased for important structures or cases
with large variation in the subsurface strata.
The methodology of carrying out load tests and of arriving at safe load on piles shall conform to IS:
2911 (Part IV).
In case of any doubt of workmanship or load carrying capacity of working piles not subjected to
routine tests, or when ordered by the Engineer, or when provided in the contract, load tests on
working piles may be supplemented by non-destructive testing. Such tests may include “Integrity
Testing” of concrete in the installed pile and utilization of “Pile Driving Analyser” which gives an
indication of pile capacity in end bearing and side friction.

B-11.18 PILE CAP

Pile Caps shall be of reinforced concrete. A minimum offset of 150 mm. shall be provided beyond
the outer faces of the outer most piles in the group. If the pile cap is in contact with earth at the
bottom, a leveling course of minimum 100 mm. thickness of M-15 nominal mix concrete shall be
provided.
The attachment of the pile head to the cap shall be adequate for the transmission of loads and
forces. A portion of pile top may be stripped off from concrete and the reinforcement anchored into
the cap. Manual chipping may be permitted after three days of pile casting, while pneumatic tools
for chipping shall not be used before seven days after pile casting. The top of pile after stripping
shall project at least 150 mm. into the pile cap. A layer of surface reinforcement may be provided
with a cover of 25 mm. to retain the integrity of concrete below the main cap reinforcement which
is to be laid 25 mm. above the pile top.
Concreting of the pile cap shall be carried out in dry conditions. The bottom of the pile cap shall be
laid preferably as low as possible taking account of the water level prevalent at the time of casting.
The top of concrete in a pile shall be brought above cut-off level to permit removal of all laitance
and weak concrete before pile cap is laid. This will ensure good concrete at the cut-off level.

B-11.19 IMPORTANT CONSIDERATIONS, INSPECTION / PRECAUTIONS FOR

DIFFERENT TYPES OF PILES
B-11.19.1 Driven Cast-In-Situ Piles
Specialist literature and the guidelines from the pile construction industry shall be consulted
regarding the method of installation, equipment and accessories for pile driving and recording of
data.
During installation of piles the final “set” of penetration of pile per blow of hammer shall be
checked taking an average of last 10 blows.

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The pile shoes which may be of either cast iron conical type or mild steel flat type shall have
double reams for proper seating of the removable casing tube inside the space between the reams.
Before commencement of pouring of concrete, it shall be ensured that there is no ingress of water
in the casing tube from the bottom. Further adequate control during withdrawal of the casing tube is
essential so as to maintain sufficient head of concrete inside the casing tube at all stages of
withdrawal.
Concrete in piles shall be cast upto a minimum height of 600 mm. above the designed tip level of
pile, which shall be stripped off at the time of construction of pile cap.
B-11.19.2 Bored Cast-In-Situ Piles
While concreting uncased piles, voids in concrete shall be avoided and sufficient head of concrete
is to be maintained to prevent in flow of soil or water into the concrete. It is also necessary to take
precautions during concreting to minimise the softening of the soil by excess water. Uncased cast-
in-situ piles shall not be allowed where mudflow conditions exist.
The drilling mud such as bentonite suspension shall be maintained at a level sufficiently above the
surrounding ground water level to ensure the stability of the strata which is being penetrated
throughout the boring process until the pile has been concreted.
Where bentonite suspension is used to maintain the stability of the bore-hole, it is essential that the
properties of the material be carefully controlled at stages of mixing, supply to the bore-hole and
immediately before concrete is placed. It is usual to limit:
(i) The density of bentonite suspension to 1.05 gm/cc

(ii) The marsh cone viscosity between 30 and 40

(iii) The pH value between 9.5 and 12

(iv) The silt content less than 1 per cent

(v) The liquid limit of bentonite not less than 400 per cent

These aspects shall act as controlling factors for preventing contamination of bentonite slurry for
clay and silt.
The bore shall be washed by bentonite flushing to ensure clean bottom at two stages viz. after
completion of boring and prior to concreting after placing of reinforcement cage. Flushing of
bentonite shall be done continuously with fresh bentonite slurry till the consistency of in-flowing
and out-flowing slurry is similar.
For very long or large diameter piles, use of retarding plasticizer in concrete is desirable.
For large diameter piles, it may be essential to conduct non-destructive pile integrity tests to
evaluate integrity of the pile.
Where possible, it may be desirable to grout the base of pile with cement slurry under suitable
pressure after concrete in the pile attains the desired strength. For this purpose, conduit pipes with
easily removable plugs at the bottom end should be placed in the bore along with reinforcement
cage before concreting.

B-11.20 TOLERANCES
B-11.20.1 Permissible Tolerances for Pile
(A) Pre-cast Concrete Piles:

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o Variation in cross-sectional dimensions : ± 5 mm

o Variation in length : ± 25 mm
o Surface irregularities measured with 3 m straight edge : 5 mm
o Bow for length in mm : Pile length
in mm 1000
(B) Driven Piles:
o Variation in cross-sectional dimensions : + 50 mm, -10 mm
o Variation from vertical or specified rake : 1 in 50
o Variation in the final position of the head in plan : 75 mm
o Variation of level of lop of piles : ± 25 mm
(C) Bored Piles:
o Variation in cross-sectional dimensions : + 50 mm, -10 mm
o Variation from vertical or specified rake : 1 in 50
o Variation in the final position of the head in plan : 75 mm
o Variation of level of lop of piles : ± 25 mm
B-11.20.2 Permissible Tolerances for Pile Caps
o Variation in dimension : +50 mm -10 mm
o Misplacements from specified position in plan : 15 mm
o Surface irregularities measured with 3 m straight edge : 5 mm
o Variation of levels at the top : ± 25 mm

B-11.21 WELL FOUNDATION

B-11.21.1 General
This work consists of construction of well foundation, taking it down to the founding level through
all kinds of sub-strata, plugging the bottom, filling the inside of the well, plugging the top and
providing a well cap in accordance with the details shown on the drawing and as per these
specifications, or as directed by the Engineer-in-Charge.
In case of well foundations of size larger than 12 m in diameter, supplemental construction
specifications will be necessary.
Well may have a circular, rectangular, or D-shape in plan and may consist of one, two or more
compartments in plan. The outer wall of the well is known as well steining which may be cellular.
The process of taking down the well to the founding level is known as well sinking. After reaching
the founding level, the hollow inside the well, (dredge hole) is plugged at the bottom by concrete
(bottom plug). The dredge hole is then filled with approved filling upto the level indicated on the
drawing and provided with a concrete plug (top plug).
To facilitate sinking of well, steel cutting edge is fabricated and connected to a concrete well curb
of required shape. On the top of well curb, adequate height of well steining is cast and the process

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of sinking is carried out. After a portion of well has been sunk, another height of well steining is
cast on top of the previous section and further sinking carried out. The process is continued till the
bottom level of the well reaches the founding level.
At the top of the well steining, an adequately designed “well cap” is laid which transmits the loads
and forces from the sub-structure (piers or abutments) to the foundations.
Well foundation may rest on any soil including rocks if the design requirements are met. In case a
well is founded on rock there should be adequate embedment and even all-round seating.
At least one bore-hole must be available/carried out in accordance with these specifications at each
well foundation location, prior to commencement of work. The depth of bore-holes should extend
upto a depth equal to 1.5 times the outer diameter/least dimension of the well below the anticipated
founding level. The results of soil exploration should be presented in accordance with Clause 7.4 of
IRC: 78. in case the well foundation is to rest on a rocky strata, it may be necessary to undertake
additional borings/ probings prior to commencement of work to ascertain the actual profile and the
quality of the rocky strata, at the level at which the well has to be seated.
Blasting may have to be resorted to in order to facilitate sinking through difficult strata, such as
boulders and rocks etc. in case blasting is anticipated, protective/strengthening measures specified
in relevant Clause of IRC: 78 shall be taken.
In case the bore hole data shoes the presence of steeply dipping rock, chiseling may have to be
resorted to so as to obtain proper seating of the foundation, for this purpose, the well may required
to be dewatered completely under high water pressure inside the well. This process is known as
pneumatic sinking. Pneumatic sinking may also have to be resorted to in cases where obstacles
such as tree trunks, large sized boulders or hard strata etc cannot be removed by open dredging. The
necessity of adopting pneumatic sinking shall be decided by the Engineer-in-Charge.
B-11.21.2 Setting out and preparations for sinking
Necessary reference points shall be fixed, away from the zone of blow-ups or possible settlements
resulting from well sinking operations. Such reference points shall be connected to the permanent
theodolite stations with the base line on the banks. The center of the individual wells shall be
marked with reference to these stations. The distance, wherever practicable, shall be checked with
the help of accurate tapes and precision distomat.
Reference points shall also be fixed to mark X-X axis (usually traffic direction) and Y-Y axis
(normal to X-X axis) accurately.
A temporary bench mark shall also be established near the well foundation, away from the zones of
blow-ups or possible settlement. The bench mark shall be checked regularly with respect to
permanent bench mark established at the bridge site.
For wells which are to be pitched in water, an earthen or sand island shall be constructed. Sand
islands are practicable for water depths of about 5 meters under stable bed soil conditions. For
greater depths or in fast flowing rivers or for locations where soil is too weak to sustain sand-island,
floating caissons may have to be adopted.
The plan dimensions of sand islands shall be such as to have a working space of at least 2 meters all
round steining. The dimensions of the sand islands shall however be not less than twice the
dimension of plan of well or caisson. Sand islands shall be maintained to perform their functions,
until the well is sunk to a depth below the bed level at least equal to the depth of water.
Sand island shall be protected against scour and the top level shall be sufficiently above the
prevailing water level to be decided by the Engineer-in-Charge so that it is safe against wave
action.

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Floating caissons may be of steel, reinforced concrete or a combination of the two. They should
have at least 1.5 m free board above water level and increased, if considered necessary, in case
there is a possibility of caissons sinking suddenly owing to reasons such as scour likely to result
from the lowering of caissons, effect of waves, sinking in very soft strata etc.
Stability of floating caissons shall be ensured against overturning and capsizing while being towed
and during sinking for the action of water current, wave pressure, and wind etc.
For floating caissons, a detailed method statement of fabrication, floating and sinking of caissons
shall be prepared and furnished to the Engineer-in-Charge. Such statement shall include the total
tonnage of steel involved, fabrication and welding specifications, list of materials and plant and a
description of operations and manpower required for the work. The caissons shall be tested for
leakages before being towed to the site.
B-11.21.3 Equipments
Equipments shall be deployed for construction of well foundation as required and as directed by the
Engineer-in-Charge. Generally, the following equipments may be required for the work:
a) Crane with grab buckets capacity 0.5 – 2.0 m3
b) Submersible pumps.
c) Air compressors, air locks and other accessories where pneumatic sinking of well is
anticipated.
d) Chisels of appropriate sizes.
e) Aqua-header for cutting rocky strata.
f) Driving helmets and accessories.
g) Equipment for concrete production, transportation placing and compaction.
B-11.21.4 Cutting Edge
The mild steel cutting edge shall be made from structural steel sections. The cutting edge shall
weigh not less than 40 kg/meter length and be properly anchored into the well curb, as shown in the
drawing.
Where there are two or more compartments in a well, the bottom end of the cutting edge of the
inner walls of such wells shall be kept at about 300 mm above that of outer walls.
The parts of the cutting edge shall be erected on level firm ground. Temporary supports shall be
provided to facilitate erection and maintaining the assembly in true shape. The fabrication may be
carried out in the shop or at site. Steel sections shall be heated and forced into shape. However, “V”
cuts may be made in the horizontal portion, uniformly throughout the length, to facilitate cold
bending. After bending such “V” cuts should be closed by welding. Joints in the lengths of
structural sections, unless otherwise specified shall be fillet welded using single cover plate to
ensure the requisite strength of the original section.
The cutting edge shall be laid about 300 mm above prevalent water level.
B-11.21.5 Well Curb
The well curb may be precast or cast-in-situ. Steel formwork for well curb shall be fabricated
strictly in conformity with the drawing. The outer face of the curb shall be vertical. Steel
reinforcements shall be assembled as shown in the drawings. The bottom ends of vertical bond rods
of steining shall be fixed securely to the cutting edge with check nuts or by welds.
The well curb shall invariably be in reinforced concrete of mix not leaner than M 25 with minimum
reinforcement of 72 kg/ m3 excluding bond rods. The steel shall be suitably arranged to prevent
spreading and splitting of the curb during sinking and in service.

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The formwork on outer face of curb may be removed within 24 hours after concreting. The
formwork on inner face shall be removed after 72 hours.
All concreting in the well curb shall be done in one continuous operation.
B-11.21.6 Well Steining
Steining may be in plain cement concrete with nominal reinforcement or in Reinforced Cement
Concrete. Cellular Steining shall not be permitted. The concrete mix in plain cement concrete
steining shall not be leaner than M 15. in case of marine or other similar conditions of adverse
exposure, the concrete in the steining shall not be less than M 20 with cement not less than 310
kg/m3 of concrete and water-cement ratio not more than 0.45. The steining shall be built up in one
straight line from bottom to top such that if the well is tilted, the next lift of steining will be aligned
in the direction of tilt. The work shall be checked carefully with straight edges of lengths approved
by the Engineer-in-Charge. Plumb bob or spirit level shall not be used for alignment. After sinking
of a stage is complete, damaged portions if any, of steining at top of the previous stage shall be
properly repaired before constructing the next stage.
The height of steining shall be calibrated by making at least 4 gauges (preferably in traffic direction
and in a direction normal to traffic direction) distributed equally on the outer periphery of the well
each in the form of a 100 mm. wide strip painted on the well, with every meter mark shown in
black paint. The gauges shall start with zero at the bottom of the cutting edge. Marking of the
gauges shall be done carefully with a steel tape.

B-11.22 WELL SINKING

B-11.22.1 General
The well shall as far as possible be sunk true and vertical through all types of strata.
Sinking or loading of the well with kentledge shall be commenced only after the steining has been
cured for at least 48 hours or as specified in the drawings.
No well shall be permitted to be placed in a pre-dredged hole.
The well shall be sunk by excavating material uniformly from the inside of the dredge hole. Use of
water jetting, explosives and divers may be adopted for sinking of wells through difficult strata
with prior approval of the Engineer-in-Charge.
Normally dewatering of well should not be permitted as a means for sinking the well. It also shall
never be resorted to if there is any danger of sand blowing under the well. Dewatering shall
however be done when the well is to be founded into rock. Pneumatic sinking may have to be
resorted to where obstacles such as tree trunks, large size boulders, etc. are met at the bottom or
when there is hard strata which cannot be removed by open dredging. The necessity for pneumatic
sinking shall be decided by the Engineer-in-Charge.
Sinking history of well shall be maintained in the format given in Appendix 1200/I of MoRTH’s
Specifications for Road and Bridge Works (4th Revision) published by IRC.
B-11.22.2 Use of Kentledge as Sinking Load
Kentledge shall be placed in an orderly and safe manner on the loading platform and in such a way
that it does not interfere with the excavation of the material from inside the dredge hole and also
does not in any way damage the steining of the well.

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Where tilts are present or there is a danger of well developing a tilt, the position of the load shall be
regulated in such a manner as to provide greater sinking effort on the higher side of the well.
B-11.22.3 Use of Water Jetting
Water jetting may be employed for well sinking wherever necessary.
B-11.22.4 Use of Explosives
Mild explosive charges may be used as an aid for sinking of the well only with prior permission of
the Engineer-in-Charge. Blasting of any sort shall only be done in the presence of the Engineer and
not before the concrete in the steining has hardened sufficiently and is more than 7 days old. When
likelihood of blasting is predicted in advance, protection of the bottom portion of the well shall be
done as per these specifications. After blasting operations are completed the well curb and steining
should be examined for any cracks and remedial measures taken.
If blasting has been used after the well has reached the design foundation level, normally 24 hours
shall be allowed to lapse before the bottom plug is laid.
The charges shall be exploded well below the cutting edge by making a sump so as to avoid
chances of any damage to the curb or to the steining of the well. A minimum sump of 1 meter depth
should be made before resorting to blasting. Use of large charges, 0.7 kg or above, may not be
allowed except under expert direction and with the permission from the Engineer. Suitable pattern
of charges may be arranged with delay detonators to reduce the number of charges fired at a time.
The burden of the charge may be limited to 1 meter and the spacing of holes may normally be kept
as 0.5 to 0.6 meters.
All prevalent laws concerning handling, storing and using of explosives shall be strictly followed.
All safety precautions shall be taken as per IS: 4081 “Safety Code for Blasting and related Drilling
Operations”, to the extent applicable, whenever blasting is resorted to.
There should be no equipment inside the well nor there do any labour in the close vicinity of the
well at the time of exploding the charges.
If rock blasting is to be done for seating of the well, the damage caused by flying debris should be
minimised by covering blasting holes by rubber mats before blasting.
B-11.22.5 Use of Divers
Use of divers may be made both for sinking purpose like removal of obstructions, rock blasting and
for inspection. All safety precautions shall be taken as per any acceptable safety code for sinking
with divers or any statutory regulations in force.Only persons trained for the diving operation shall
be employed and shall be certified to be fit for diving by an approved doctor.
They shall work under expert supervision. The diving and other equipments shall be of acceptable
standard and certified to this effect by an approved independent agency. It shall be well maintained
for safe use.
Arrangement for ample supply of low pressure clean cool air shall be ensured through an armoured
flexible hose pipe. Standby compressor plant shall be provided in case or breakdown.
Separate high pressure connection for use of pneumatic tools shall be made. Electric lights where
provided shall be at 50 volts (maximum). The raising of the diver from the bottom of wells shall be
controlled so that decompression rate conforms to the rate as laid down in appropriate regulations.
B-11.22.6 Use of Pneumatic Sinking
The Engineer-in-Charge shall familiarize himself with particular reference to caisson diseases and
working of the medical air-lock. A doctor competent to deal with cases of “Caisson Diseases” or

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other complications arising as a result of working under high pressure, shall be stationed at the
construction site when pneumatic sinking is under progress.
The Contractor shall provide complete facilities including issuing of orders to ensure strict
enforcement of the requirements outlined in the MoRTH’s Specifications for Road and Bridge
Works (4th Revision) published by IRC. For other details the relevant clauses of this book may be
referred to.
B-11.22.7 Precautions during Sinking
(a) When the wells have to be sunk close to each other and clear distance between them is not
greater than the diameter of wells, sinking shall be taken up on all wells and they shall be
sunk alternately so that sinking of wells proceeds uniformly. Simultaneous and even dredging
shall be carried out in the wells in such a manner that the difference in the levels of the sump
and cutting edge in the adjacent wells does not exceed half the clear gap between them.
Plugging of all the wells shall be done together.
(b) During sinking of dumb-bell or double D-shaped wells, the excavation in both the dredge
boles should be carried out simultaneously and equally.
(c) Bore chart shall be referred to constantly during sinking for taking adequate care while
piercing different types of strata. The type of soil as obtained during the well sinking should
be compared with bore chart so as to take prompt decisions.
(d) Before seasonal floods all wells on which sinking is in progress shall be sunk to sufficient
depths below the designed scour level. Further, they shall be temporarily filled and plugged
so that they do not suffer any tilt or shift during the floods.
(e) All necessary precautions shall be taken against any possible damage to the foundations of
existing structure in the vicinity of the wells, prior to commencement of dredging from inside
the well.
(f) The dredged material shall not be allowed to accumulate over the well. It shall be dumped
and spread, as far away as possible, and then continuously and simultaneously removed, as
directed by the Engineer-in-Charge. In case the river stream flows along one edge of the well
being sunk, the dredged material shall not be dumped on the dry side of the bank nut on the
side on which the river current flows.
(g) Very deep sump shall not be made below the well curb, as it entails risk of jumping (sudden
sinking) of the well. The depth of sump shall be generally limited to one-sixth of the outer
diameter/least lateral dimension of the well in plan. Normally, the depth of sump shall not
exceed 3.0 meters below the level of the cutting edge unless otherwise specifically permitted
by the Engineer-in-Charge.
(h) In case a well sinks suddenly with a jerk, the steining of the well shall be examined to the
satisfaction of the Engineer to se that no damage has occurred to it.
(i) In pneumatic sinking, the well shall not, at any time, be dropped to a depth greater than 500
mm by the method of “blowing down.”
(j) Dewatering shall be avoided if sand blows are expected. Any equipment and men working
inside the well shall be brought out of the well as soon as there are any indications of a sand-
blow.
(k) Sand blowing in wells can often be minimized by keeping the level of water inside the well
higher than the water table and also by adding heavy kentledge.

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(l) In soft strata prone to settlement / creep, the construction of the abutment wells shall be taken
up only after the approach embankment for a sufficient distance near the abutment has been
completed.
B-11.22.8 Tilts and Shift
The inclination of the well from the vertical is known as tilt and the horizontal displacement of the
centre of the well at the founding level from its theoretical position is known as shift.
Unless otherwise specified, the tilt of any well shall not exceed 1 (horizontal) in 80 (vertical), and
the shift at the well base shall not be more than 150 mm in any resultant direction.
Tilts and shifts shall be carefully checked and recorded in the format vide Appendix 1200/II of
MoRTH’s Specifications for Road and Bridge Works (4th Revision) published by IRC regularly
during sinking operations. For the purpose of measuring the tilts along the two axes of the bridge
reduced level of the marks painted on the surface of the steining of the well shall be taken. For
determination of shift, locations of the ends of the two diameters shall be precisely measured along
the two axes, with reference to fixed reference points.
Whenever any tilt is noticed, adequate preventive measures like placing eccentric kentledge,
pulling, strutting, anchoring or dredging unevenly and depositing dredge material unequally,
putting obstacles below cutting edge. Water jetting etc. shall be adopted before any further sinking.
After correction, the dredged material shall be spread out uniformly.
A pair of wells close to each other has a tendency to come closer while sinking. Timber struts may
be introduced in between the steining of these wells to prevent tilting.
Tilts occurring in a well during sinking in dipping rocky strata can be safeguarded by suitably
supporting the curb.
In the event of a well developing tilt or shift beyond the specified permissible values, the contractor
shall have to carry out at his own cost, suitable remedial measures to the satisfaction of the
Engineer to bring the tilt and shift within permissible values, as far as practicable.
If the resultant tilt and / or shift of any well exceed the specified permissible values, generally it
should not exceed 1 in 50 and 300 mm respectively. The well so sunk shall be regarded as not
conforming to specifications and a sub-standard work. The Engineer-in-Charge in his sole
discretion may consider accepting such a well provided:
(i) Calculations for foundation pressures and steining stresses, accounting for the actual tilt and
shift furnished by the Contractor so that the well is safe. Any remedial measures required to
bring to stresses within permissible values (such as increase in the dimension of the well cap
provision of dummy weights on the well cap etc., shall be carried by the Contractor without
chaining
(ii) The Contractor shall agree to reduction in rates in accordance with tender condition.
In case the Engineer-in-Charge, in his discretion, rejects the well, the Contractor shall dismantle the
rejected well to the extent directed by the Engineer-in-Charge and remove the debris. Further the
Contractor shall at his own risk and expense complete the bridge with modified span arrangement
acceptable to the Engineer-in-Charge.
B-11.22.9 Seating of Wells
The well shall be uniformly seated at the founding strata. It shall be ensured by the test borings that
the properties of the soil encountered at the founding strata and upto a depth of one and a half times
the well diameter is identical to that adopted in the design. The procedure for test borings shall
satisfy the provision of these specifications. In case the soil encountered is inferior to the adopted in

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design, the well shall be re-designed by the Engineer adopting the soil properties actually
encountered and the founding level intimated to the Contractor, who shall carry out the work.
In case of seating of well in hard rocky strata, where the rock profile is steeply sloping, pneumatic
methods of sinking may be adopted to seat the well event as directed by the Engineer-in-Charge.
The decision of adopting pneumatic sinking shall be taken by the Engineer-in-Charge. The cutting
edge may also be embedded for a suitable depth in the rocky strata, as decided by the Engineer-in-
Charge keeping in view the quality of rock. As an additional measure of safety, the well shall be
anchored to the rocky strata by anchor bars provided in the steining of the well, as shown on the
drawing irrespective of the fact that tension develops or not at the base of the well under design
loads. After the well has been evenly seated on good hard rock, arrangements shall be made to
facilitate proper inspection in dry and visible conditions before the bottom plug is laid.
B-11.22.10 Bottom Plug
For bottom plug, the concrete mix shall be designed (in dry condition) to attain the concrete
strength as mentioned on the drawing and shall contain 10 % more cement than that required for the
same mix placed dry, to cater for underwater concreting. The concrete mix used in the bottom plug
shall have a minimum cement content of 363 kg/ m3 with a slump of about 150 to 200 mm.
Admixture may be added to the concrete to impart the required characteristics indicated herein.
Concrete for the bottom plug shall be laid by tremie pipe method. Tremie concrete when started
shall be continued without interruption for full concreting in the bottom plug. The concrete
production equipment and placement equipment should be sufficient to enable under water
concreting within stipulated time. Necessary standby equipment should be available for emergency
situation.
Before commencing plugging, all loose materials from the bottom of the well shall be removed.
Concreting shall be done in one continuous operation till the dredge holes filled upto the required
height and thereafter sounding shall be taken to ensure that the concrete has been laid to the
required height.
Least disturbance shall be caused to the water inside the well while laying concrete in the bottom
plug.
Concrete shall not be disturbed in any way for at least 14 days. In order to check any rise in the
level of the bottom plug, soundings should be taken at the close of concreting and once every day
for the subsequent 3 days.
The soundness of the bottom plug may be tested by dewatering the well by 5 meters below the
surrounding water level and checking the rise of water. The rate of rise shall preferably be less than
10 cms per hour. In case the rate is higher, suitable remedial measures as directed by the Engineer-
in-Charge shall be taken by the Contractor at his own cost.
B-11.22.11 Sand filling
Sand filling shall commence after a period of 3 days of laying of bottom plug. Also the height of
the bottom plug shall be verified before starting sand filling.
Sand shall be clean and free from earth, clay clods, roots, boulders, shingles, etc. and shall be
compacted as directed. Sand filling shall be carried out upto the level shown on the drawing or as
directed by the Engineer-in-Charge.
B-11.22.12 Top Plug
After filling sand upto the required level a plug of concrete shall be provided over it as shown on
the drawing or as directed by the Engineer-in-Charge.

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B-11.22.13 Well Cap

A reinforced cement concrete well cap will be provided over the top of the steining in accordance
with the drawing. Formwork will be prepared conforming to the shape of well cap. Concreting shall
be carried out in dry condition. A properly designed false steining may be provided where possible
to ensure that the well cap in laid in dry conditions.
The bottom of the well cap shall be laid preferably as low as possible, taking account the water
level prevalent at the time of casting.
B-11.22.14 Tolerances
The permissible tilt and shift shall not exceed 1 (horizontal) in 80 (vertical) and the shift at the well
base shall not be more than 150 mm. in any resultant direction.
For the well steining and well cap the permissible tolerances shall be as follows:
i. Variation in dimension : +50 mm, – 10 mm.
ii. Misplacement from specified position in plan : 15 mm.
iii. Surface irregularities measured with 3 m. straight edge : 5 mm.
iv. Variations of levels at the top : ± 25 mm
B-11.22.15 Mode of measurements for payment
The measurement for cutting edge under the curb shall be in tones based on the net weight of metal
used in it. The curb, well steining and well cap shall be measured in cubic meters. The steel used in
these works shall be measured as reinforcement.
The measurement for well sinking shall be made in running meters for different depths as specified
in the contract. The quantity of bottom and top plugging concrete and soil filling shall be measured
in cubic meters.

B-12 BRICK MASONRY

Brick work shall be of 1st class brick laid in English bond with mortar as per specification of the
item. Cutting of bricks as required are covered in the rates for relevant items of brick work and
hence no extra shall be allowed for this.
Sand, lime, and surki for mortar shall be measured by volume in properly constructed boxes and
cement by bags of 0.035 m3 per 50 kg. bag. The materials shall be thoroughly mixed dry to an even
colour and requisite quantity of water added to form workable mix of proper consistency.
Cement mortar shall be mixed in small quantities at such rate as no mortar mixed over half an hour
is used. The mortar joints in bricks shall be of uniform thickness of 7.5 mm and with such tolerance
as may be considered reasonable by the Engineer-in-Charge. All brick work shall be kept
thoroughly wet. Bricks are to be well-soaked in water before use. No brick work shall be carried
more than one scaffolding height of 1.20 m. to 1.50 m. above adjoining walls.
The surface of walls shall be kept clean and joints raked about 1.25 cm. deep for pointing or
plastering whilst the mortar is fresh. Necessary scaffolding is to done by contractor at his own cost
and responsibility and nothing extra will be paid for that.

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B-13 WEARING COAT AND APPURTENANCES

Description
This work shall include wearing coat and bridge appurtenances such as railing, approach slab,
drainage spouts, weep holes in conformity with details shown on the drawing and these
specifications or as approved by the Engineer-in-Charge.

B-13.1 WEARING COAT

B-13.1.1 Bituminous Wearing Coat
Specifications for bituminous concrete / bitumen mastic in wearing coat shall conform to Section
B-10 for the special requirements as stated hereinafter.
Principles of bituminous wearing coat shall comprise the following:
(a) A layer of mastic asphalt, 6 mm thick after applying a prime coat over the top of the deck before
the wearing coat is laid. The prime coat and the layer of mastic asphalt shall be laid as per Section
B-10.
(b) 50 mm thick asphaltic concrete wearing coat in two layers of 25 mm each as per Section B-10.
In case of high rainfall intensity areas, the thickness of mastic asphalt layer may be increased to 12
mm.
For high traffic density, an alternative specification for wearing course comprising 40 mm
bituminous concrete overlaid with 25 mm. thick bitumen mastic layer can be adopted. The work
shall be done in conformity with Section B-10.
B-13.1.2 Cement Concrete Wearing Coat
Cement concrete wearing coat may be provided in case of isolated bridge construction or bridges
located in remote areas. It shall not be laid monolithic with the deck.
The thickness of wearing coat shall be 75 mm. The minimum grade of concrete shall be M 30 with
water cement ratio as 0.4.
Curing of wearing coat earlier than what is generally required may be resorted to, so as to avoid
formation of shrinkage cracks in hot weather.
All carriageway and footpath surfaces shall have non-skid characteristics.
The cross slope in the deck shall be kept as 2.5 per cent for decks, level in longitudinal profile.
For providing cross camber no variation in thickness of wearing coat shall be permitted.

B-13.2 RAILING
B-13.2.1 General
Bridge railing includes the portion of the structure erected on and above the kerb for protection of
pedestrians and traffic.
Railings shall not be constructed until the centering false work for the span has been released and
the span is self-supporting. For concrete with steel reinforcement specifications of the items of
controlled concrete and reinforcement mentioned under relevant sections of this specification shall
be applicable.

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The type of railing shall be carefully erected true to line and grade. Posts shall be vertical with a
tolerance not to exceed 6 mm. in 3 meters. The pockets left for posts shall be filled up with non-
shrinkable mortar.
The type of railing to be constructed shall be as shown on the drawings.
Care shall be exercised in assembling expansion joints in the railings to ensure that they function
properly.
The bridge railings shall be amenable to quick repairs.
Railing materials, particularly metal railings, shall be handled and stored with care, so that the
material and parts are kept clean and free form damage. Railing materials shall be stored above the
ground on platforms, skids, or other supports and kept free from grease dirt and other contaminants.
Any material which is lost, stolen or damaged after delivery shall be replaced or repaired by the
Contractor, Methods of repair shall not damage the material or protective coating.
B-13.2.2 Metal Railings
Materials, fabrication, transportation, erection and painting for bridge railing shall conform to the
requirements of Section 1900 of MoRTH’s Specifications for Road and Bridge Works (4th
Revision) published by IRC.
All complete steel rail elements, pipe terminal sections, posts, bolts, nuts, hardware and other steel
fittings shall be galvanized or painted with an approved paint.
If galvanized, all elements of the railing shall be free fro abrasions, rough or sharp edges and shall
not be kinked, twisted or bent. If straightening is necessary, it shall be done by methods approved
by the Engineer-in-Charge.
Damaged galvanized surfaces edges of holes and ends of steel railing cut after galvanizing shall be
cleaned and re-galvanized.
The railing shall be carefully adjusted prior to fixing in place to ensure proper matching at abutting
joints and correct alignment and camber throughout their length. Hole for field connection shall be
drilled with the railing in place in the structure at proper grade and alignment.
Unless otherwise specified on the drawings, metal railing shall be given one shop coat of paint and
three coats of paint after erection if sections are not galvanized.
Railing shall not follow any irregularity in the alignment of the deck. When shown on the drawings,
the rail elements shall be curved before erection.
B-13.2.3 Cast-In-Situ Concrete Railings
The portion of the railing or parapet which is to be cast in place shall be constructed in accordance
with the requirements for Structural Concrete in Section B-11; the reinforcement shall conform to
Section B-11. Form shall either be of single width boards or shall be lined with suitable material
duly approved by the Engineer-in-Charge. Form joints in plane surfaces will not be permitted.
All mouldings, panel work and bevel strips shall be constructed according to the details shown on
the drawings. All corners in the finished work shall be true, sharp and clean-cut and shall be free
from cracks, spalls or other defects. Casting of posts shall be done in single pour.
B-13.2.4 Precast Concrete Railings
Precast members for railings shall be of reinforced cement concrete and shall conform to the
specifications given in Sections B-11. The maximum size of the aggregate shall be limited to 12
mm and the concrete grade shall be M 30.

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The precast members shall be removed from the moulds as soon as practicable and shall be kept
damp for a period of at least 10 days. During this period they shall be protected from sun and wind.
Any precast member that becomes chipped, marred or cracked before or during the process of
placing shall be rejected. Special care shall be taken to watch the surface of the cast-in-situ portion
of the deck.

B-13.3 APPROACH SLAB

Reinforced concrete approach slab covering the entire width of the roadway shall be provided as
per details given on the drawings or as approved by the Engineer-in-Charge. Minimum length of
approach slab shall be 3.5 m and minimum thickness 300 mm.
The cement concrete and reinforcement shall conform to Sections B-11 respectively. The base for
the approach slab shall be as shown on the drawings or as directed by the Engineer-in-Charge.

B-13.4 DRAINAGE SPOUTS

This work shall consist of furnishing and fixing in position of drainage spouts and drainage pipe for
bridge decks.
Drainage along longitudinal direction shall be ensured by sufficient number of drainage fixtures
embedded in the deck slab. The spouts shall be of not less than 100 mm in diameter and shall be of
corrosive resistant material such as galvanized steel with suitable cleanout fixture. The spacing of
drainage spouts shall not exceed 10 m. The discharge from drainage spout shall be kept away from
the deck structure. In case of viaducts in urban areas, the drainage spouts should be connected with
suitably located pipelines to discharge the surface run-off to drains provided at ground level.
B-13.4.1 Fabrication
The drainage assembly shall be fabricated to the dimensions shown on the drawings; all materials
shall be corrosion resistant; steel components shall be of mild steel conforming to IS: 226. The
drainage assembly shall be seam welded for water tightness and then hot-dip galvanized.
B-13.4.2 Placement
The galvanized assembly shall be given two coats of bituminous painting before placement. The
whole assembly shall be placed in true position, lines and levels as shown in the drawings with
necessary cut-out in the shuttering for deck slab and held in place firmly. Where the reinforcements
of the deck are required to be cut equivalent reinforcements shall be placed at the corners of the
assembly.
B-13.4.3 Finishing
After setting of the deck slab concrete, the shrinkage cracks around the assembly shall be totally
sealed with polysulphide sealant or bituminous sealant as per IS: 1834 and the excess sealant
trimmed to receive the wearing coat. After the wearing coat is completed, similar sealant shall be
finished to cover at least 50 mm on the wearing coat surface all round the drainage assembly.

B-13.5 WEEP HOLES

Weep holes shall be provided in solid plain concrete / reinforced concrete brick / stone masonry,
abutment, wing wall and return walls as shown on the drawing or directed by the Engineer-in-
Charge to drive moisture from the back filling. Weep holes shall be proved with 100 mm dia AC

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pipe for structures in plain / reinforced concrete or brick masonry. In case of stone masonry, weep
holes shall be 80 mm wide, 150 mm high or circular with 150 mm diameter. Weep holes shall
extend through the full width of concrete / masonry with slope of about 1 vertical: 20 horizontal
towards the draining face. The spacing of weep holes shall generally be 1 m in either direction or as
shown in the drawing with the lowest at about 150 mm above the low water level or ground level
whichever is higher or as directed by the Engineer-in-Charge.

B-13.6 TESTS & STANDARDS OF ACCEPTANCE

The materials shall be tested in accordance with these Specifications and shall meet the prescribed
criteria. The work shall conform to these Specifications and shall meet the prescribed standards of
acceptance.

B-13.7 MEASUREMENTS FOR PAYMENTS

The measurement for payment foe wearing coat, railings and approach slab shall be made as given
below:
Cement concrete wearing coat : Cubic meter (m3)
Asphaltic concrete wearing coat : Square meter (m2)
Railing : Running meter (m)
Approach slab and its base (Separate : Cubic meter (m3)
item)
Drainage Spouts : Numbers (Each)
Weep holes in concrete/Brick masonry : Numbers (Each)
structure
Weep holes in Stone masonry works : Weep holes shall be deemed to be included in the
item and hence shall not be measured separately.

B-14 SURFACE & SUB-SURFACE GEOTECHNICAL EXPLORATION

B-14.1 GENERAL
The objective of sub-surface exploration is to determine the suitability or otherwise of the soil or
rock surrounding the foundation and soil parameters and rock characteristics for the design of
foundation by in-situ testing or testing of samples/ cores taken out of exploration. The sub-surface
exploration shall be planned in such a way that different type of soil upto the desired depth and
their profile for the full proposed length of the bridge can be recorded and other information such as
mechanical and physical properties like grain-size distribution, sensitivity, any existence of
deleterious material in soil or ground, water, etc., are determined along with soil parameters and
rock characteristics. The sub-surface exploration shall also throw light on porosity of rock and
subsidence due to mining, ground water level, artesian condition, if any, likely sinking and driving
effort, likely constructional difficulties, etc.

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B-14.2 FIELD INVESTIGATION
Field investigation of sub-surface has usually three phases:
(a) Reconnaissance
(b) Preliminary Explorations
(c) Detailed Explorations
Reconnaissance includes a review of available topographic and geological information, aerial
photographs and data from previous investigations and site examination.
Preliminary investigation shall include the study of existing geological information, previous site
reports, geological maps, air photos, etc. and surface geological examination. For large and
important structures the information may be supplemented by geophysical methods. In some cases
where no previous sub-strata data are available, exploratory geophysical investigation may need to
be supplemented by resorting to a few bore-holes. These will help to narrow down the number of
sites under consideration and also to locate the most desirable location for detailed sub-surface
investigation like bore or drill holes, sounding probes, etc.
The scope of detailed investigation for bridges may be decided based on data obtained after
preliminary investigation. Based on data obtained after preliminary investigations, the bridge site,
type of structure with span arrangement and the location and type of foundations, shall be
tentatively decided. Thereafter, the scope of detailed investigation including the extent of
exploration, number of bore-holes, type of soundings, type of tests, number of tests, etc. shall be
decided, so that adequate data considered to be necessary for the detailed design and execution, are
obtained.

B-14.3 THE WIDTH OF EXPLORATION

One purpose of detailed exploration for high embankments is to ascertain the average shear
strength of each stratum. The other purpose is to ascertain the compressibility of the slayer strata. It
is therefore, necessary that detailed and well illustrated description of the characteristics of
stratification should be prepared. After the general shape and trend of the boundaries of the various
soil deposits have been determined and rough assessment of their strength has been made by sub-
surface sounding, with or without sampling in exploratory boring, the location of bore-hole(s) for
undisturbed sampling shall be decided. At least one representative undisturbed sample should be
collected from each stratum. When the homogeneous stratum is very thick, one representative
sample shall be collected for each 3 m thickness of the stratum.
Soil investigation for foundation shall contain a programme for boring and retrieval of samples.
The field work shall consist of excavation, drilling of bore-holes for the purpose of collection of
undisturbed and disturbed samples, standard penetration tests, in-situ vane tests, static and dynamic
cone penetration tests, other field tests, as specified by the Engineer and preparation of bore-logs.
Collection and preservation for testing of disturbed and undisturbed samples from bore-holes,
borrow pits, etc., as specified by the Engineer shall form a part of the above. All in-situ tests shall
be supplemented by laboratory investigation. Relevant Indian Standards such as IS: 1498, IS: 1888,
IS: 1892, IS: 2131, IS: 2132, IS: 2720, IS: 4434 and IS: 4968 and Appendix I of IRC: 78, etc., shall
be followed for guidance.
The soundings by dynamic method shall be carried out in bore-holes using a standard sampler as
specified in IS: 2131.

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B-14.4 PRELIMINARY INVESTIGATION

B-14.4.1 Foundations
Preliminary exploration shall be carried out to determine the soil profile showing the boundaries
between the different soil types and between loose and dense parts in the same type of deposits. For
guidance reference may be made to IRC: 75. For this purpose, as a first step, a suitable type of sub-
surface sounding (e.g. static or dynamic cone penetration lest) shall be carried out. As many
soundings as necessary should be made, until the penetration data is complete enough to leave no
doubt concerning the general shape and the trend of boundaries of the various soil deposits.
Exploratory drill holes should then be made at one or two locations where average condition
prevails and near those few points where the penetration diagrams indicate maximum deviations
from the average.
The exploration shall cover the entire length of the bridge and also extend at either side for a
distance about twice the depth below bed of the last main foundations. If there is any necessity for
designing investigation for approaches particularly on soft soil or with high embankment or there is
a possibility of considering alternatives between viaduct or earthen embankment, the extended
length and location of the borings beyond the proposed location of abutment should be determined
and executed.
The depth of exploration should be at least 1½ times the minimum width of foundation below the
proposed foundation level. Where such investigation and in any unsuitable or questionable
foundation material the exploration shall be extended to a sufficient depth into firm and stable soils
or rock but not less than four times the minimum depth of foundation blow the earlier contemplated
foundation level. In case of good sound rock the stipulation of minimum depth may be decreased
based on difficulty to conduct core drilling and the minimum depth may be restricted to 3 meters.
B-14.4.2 Guide Bundh and Embankment
The depth of exploration should include all strata likely to affect stability of the embankment, guide
bundh and/or cause undesirable settlement. In general, the requirement of settlement governs the
depth of exploration for high embankments in particular. However, borings can be terminated at
shallower depths when firm strata or bed rock is encountered. Ordinarily, the boring shall be taken
to a depth of at least 1.5 times the height of embankment and guide bundh. However, where highly
compressible strata are encountered, the boring may have to be taken deeper. In order to ensure that
firm stratum is sufficiently thick, the boring should extend 3 mete into the firm stratum.

B-14.5 DETAILED EXPLORATION

The exploration shall cover the entire length of the bridge and also extend at either end for a
distance of about twice the depth below bed of the last main foundation to assess the effect of the
approach embankment on the end foundations. Generally the sub-surface investigations
(preliminary and detailed) for bridges shall extend to a depth below the anticipated foundation level
equal to about one and a half times the width of the foundation. However, where such
investigations end in any unsuitable or questionable foundation material, the exploration shall be
extended to a sufficient depth into firm and stable soils or to rock.
The type and extent of exploration shall be divided into the following groups as per requirement of
foundation design and likely method of data collection:
(a) Foundations requiring shallow depth of exploration.
(b) Foundations requiring large depth of exploration.
(c) Fills behind abutments and protection works.

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B-14.5.1 Location Boring
Where the data made available by detailed exploration indicates appreciable variation or where
variations in a particular foundation are likely to appreciably affect the construction (specially in
case of bridge foundations resting on rock), it will be necessary to resort to additional
bores/soundings to establish complete profile of the underlying strata. The additional
borings/soundings shall be decided depending upon the extent of variation at a particular
foundation location and should cover the entire area of the particular foundation.
B-14.5.2 Construction Stage Exploration
Whenever a charge in the sub-soil strata/rock profile in encountered during construction,
explorations shall be resorted to establish the correct data for further decisions.
Logging of bore-holes by radio-active methods shall be done for detailed investigations as specified
in the Contract or in special provisions.
For bridge works, the investigations shall be comprehensive enough to enable the designer to
estimate or determine the following:
(a) The engineering properties of the soil/rock.
(b) The location and extent of soft layers and gas pockets, if any under the hard
founding strata.
(c) the geological condition like type of rock, faults, fissures or subsidence due to
mining, porosity etc.,
(d) The ground water level.
(e) Artesian condition, if any
(f) Quality of water in contact with the foundation
(g) The depth and extent of scour.
(h) Suitable depth of foundation
(i) The bearing capacity of the foundation.
(j) Probable settlement and probable differential settlement of the foundations.
(k) Likely sinking or driving effort, and
(l) Likely construction difficulties.

B-14.6 EXPLORATION FOR BRIDGE FOUNDATION RESTING ON ROCKS

Investigation and interpretation of data for rock is a specialized work. To arrive at the characteristic
strength of rock mass, reliance shall be placed more on in-situ-tests in comparison to laboratory
tests. An engineering geologist shall also be associated in the exploration programme.
Identification and classification of rock types for engineering purposes may in general be limited to
broad, basic geological classes in accordance with accepted practice. Strength of parent rock alone
is of limited value because orverall characteristics depend considerably on character, spacing and
distribution of discontinuities of the rock mass, such as the joints, bedding planes, faults and
weathered seams. An important, factor affecting the behaviour is the weathered zone at top.
B-14.6.1 Basic Information Required from Explorations
(a) Depth of rock strata and its variation over the site.
(b) Whether isolated boulder or massive rock formation.

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(c) Extent and character of weathered zone.

(d) Structure of rock – including bedding planes, faults, fissures solution cavities etc.
(e) Properties of rock material-strength geological formation, etc.
(f) Erodibility of rock to the extent possible.
(g) Colour of water.
B-14.6.2 Exploration Programme
If preliminary investigations have revealed presence of rock within levels where the foundation is
to rest, it is essential to take up detailed investigation to collect necessary information mentioned in
Clause B-14.5. The exploratory bore-hole shall be drilled into the rock to a depth of about 3 meters
to distinguish a boulder from a continuous rock formation.
The extent of exploration shall be adequate enough to give a complete picture of the rock profile
both in depth and across the channel width to assess the constructional difficulties in reaching the
foundation levels.
The depth of boring in rock depends primarily on local geology, erodability of the rock, extent of
structural loads to be transferred to foundation etc. Normally, it shall pass through the upper
weathered or otherwise weak zone, well into the sound rock. Minimum depth of boring in sound
rock shall be 3 meters.
B-14.6.3 Detailed Investigation for Rock
This covers sounding, boring and drilling. An adequate investigation programme shall be planned
to cover the whole area for general characteristics and in particular the foundation location, to
obtain definite information regarding rock-depth and its variation over the foundation area. The
detailed programme of exploration will depend on the type and depth of over-burden, the size and
importance of the structure, etc. To decide this, geophysical method adopted at the preliminary
investigation stage will be helpful, this data being supplemented by sounding, bore-holes and drill
holes.
Drilling through rock is a very specialized work and every care shall be taken to notice and record
any small change during drilling. The time required to drill through a certain depth, amount of core
recovery, physical condition, length of pieces of core, joints, colour of water residue, weathering
and evidence of disturbance and other effects shall be carefully noticed and entered in the drilling
log. For guidance, IS:5313 may be referred to. The data shall be presented in accordance with IS:
4464. The cores shall be stored properly in accordance with IS:4078.
The rock cores obtained shall be subjected to following laboratory tests :
(a) Visual identification for texture, structure, composition colour and grain size.
(b) Laboratory tests shall be done for specific gravity, porosity and moisture content.
In situ tests shall be made in accordance with IS:7292; IS:7317 and IS:7746. In addition, laboratory
tests can also be made on samples.
Use of in-situ tests for measuring strength and deformation characteristics shall be made. Use of
bore-hole photography will be desirable to evaluate the presence of faults, fissures or cavities, etc.
B-14.6.4 Special Cases
B-14.6.4.1 Investigation for conglomeration:
A drill hole shall be made same as for rock. The samples collected shall be subjected to suitable
tests depending upon the material, special care shall be taken to ascertain erodibility of the matrix.
Where possible specially for shallow foundation, Plate Load Test shall be conducted.

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B-14.6.4.2 Investigation for laterites :
The investigation shall be generally similar to that required for cohesive soils, use of penetration
tests shall be preferred, if suitable correlation charts are available. This may be static or dynamic
penetration tests or vane shear tests. In the case of hard laterite, recourse may have to be made to
core drilling as for soft rocks. For laterites at shallow depths, use of Plate Load Test may be
advantageous.
B-14.6.5 Precaution
The interpretation of laboratory results on rock samples depends upon the relationship of the
specimens tested to the overall rock characteristics, enumerated in Appendix 1 of IRC:78. For this
purpose, care shall be exercised in the choice of specimen size and its orientation in relation to the
joint pattern.
In some cases, the foundation behaviour will be dominated by a possible mode of failure involving
movement along some joint surfaces fissures or weak layer within a generally strong rock system
and also be possible weathering. In situ shear tests may be conducted wherever feasible, as such
tests are likely to give more representative data than the shear tests conducted on core samples.
B-14.6.6 Presentation of Data
The data shall be given in diagrammatic form in 3 sheets giving the following details.
Sheet 1 : Plan showing the position of bore-holes clearly marked so as to fix the position at a future
date.
Sheet 2 : This shall contain the bore-log chart and test results of the samples separately for each
bore-hole / pit etc.
Sheet 3 : This shall contain pictorial representation of the bore-log data to get an overall picture of
the soil profile at the cross-section of the river. (Note: For guidance, refer to IRC:78.)

B-14.7 BORING
Boring shall be done by any of the following methods depending on the soil type and types of
samples required for the investigation:
i) Auger Boring
ii) Shell and Auger Boring
iii) Percussion Boring
iv) Wash Boring
v) Rotary Boring
For preliminary and detailed sub-surface investigation only rotary drills shall be used. The casing
shall also be invariably provided with diameters not less than 150 mm upto the level or rock, if any.
However, use of percussion or wash boring equipment shall be permitted only to penetrate through
bouldery or gravelly strata for progressing the boring but not for the collection of samples. While
conducting detailed borings, the resistance to the speed of drilling i.e. rate of penetration, core loss,
etc., as already specified in Appendix 3 of IRC: 78 shall be carefully recorded to evaluate the
different types of strata and to distinguish specially sand from sandstone, clay from shale, etc.

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B-14.8 RECORDS OF BORING & TRIAL PITS

The field records for the preliminary and detailed exploration shall contain the date when the boring
was made, the location of the boring with reference to a permanent system of co-ordinates and the
elevation of the ground surface with respect to a permanent bench mark. They shall include
elevation at which the water table and the upper boundary of each of the successive soil strata were
encountered, the investigator’s classification of the layer on the basis of general information
obtained from field examination (refer to Appendix 2.1 of IRC:75) and the value of the resistance
obtained by means of Standard Penetration Test. The type of tools used for borings shall be
recorded. If the tools were changed, the depth at which the change was made and the reason thereof
shall also be noted. Incomplete and abandoned borings shall be described with no less care than
successfully completed drill holes. The notes shall contain everything of significance observed on
the job such as the elevation at which wash water was lost from the hole.
For all borings and trial pits, necessary information as detailed below shall be given. A site plan
showing the disposition of the bore holes shall also be attached:
(i) Agency.
(ii) Location with reference map.
(iii) Pit/Bore-hole number.
(iv) Reduced level (R.L.) of ground surface or other reference point.
(v) Dates of starting and completion.
(vi) Name of supervisor.
(vii) Scales of plans and sections.
(viii) Dimensions, methods of advancing exploration such as by hand tools, blasting, boring, etc.
(ix) General description of strata met with and RLs at which they are met.
(x) Position and altitude of contacts, faults, strong joint, slicken sides, etc.
(xi) Inflow of water, methods of controlling the water, required capacity of pumps for
dewatering.
(xii) The level at which the sub-soil water is met with.
(xiii) Dip and strike of bedding and of cleavage.
(xiv) Visual description of strata.
(xv) Results of field tests e.g. SPT, in-situ vane shear test etc.
(xvi) Any other information and remarks.
Upon removal of sampling tube, the length of the sample in the tube and the length between the top
of the tube and the top of the sample in the tube shall be measured and recorded.
B-14.9 METHODS OF SAMPLING
There are two types of samples viz. (a) Disturbed sample (b) Undisturbed sample. The usual
methods for sampling conforming to IS:1892 and IS:2132 are given in Table B 14.9-1 :
Table B 14.9-1:METHODS OF SAMPLING
Test material Type of Sample Method of Sampling
Hand samples.
Disturbed Auger samples.
Soil Shell samples.
Hand samples.
Undisturbed
Tube samples.
Disturbed Wash samples from percussion or rotary drilling.
Rock
Undisturbed Cores.

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B-14.10 PROCEDURE FOR TAKING SAMPLES
For proper identification of sub-surface material, sample should be recovered containing all the
constituents of the materials in their proper proportion. In clayey deposits such samples could be
collected by split spoon samplers. In the case of sandy deposits, sampling spoons shall be fitted
with suitable devices for retaining samples. All data required for soil identification (Appendix 2.1
of IRC: 75) should be collected from the samples so extracted when undisturbed samples, which
are more desirable for collection of some of the data, are not available. Penetration test should be
carried out with the standard split spoon sampler or penetrometers if the soil is coarse grained.
When it is known in advance that the soil profile is fairly regular, preliminary and detailed
investigation may be combined. Tube samplers can be used in place of split spoon samplers for
collecting samples in clayey strata.
B-14.10.1 Disturbed Soil Samples
Disturbed samples of soil shall be obtained in the course of excavation and boring. For procuring
samples from below the ground water level, where possible, special type of sampler shall be used.
Where Standard Penetration test is conducted, representative samples shall be obtained from the
split spoon. While collecting disturbed samples from borrow areas it shall be ensured that the
samples collected represent all types of borrow materials to be used in the construction of
embankment and sub-grade.
The size of sample generally required shall be as given in Table B 14.10-1:
Table B 14.10-1: SIZES OF SAMPLES REQUIRED
Sl.No. Purpose of Sample Soil type Weight of Sample
required (Kg)
Soil identification, natural moisture content Cohesive soils and sand. 1
1. tests mechanical analysis and index properties,
chemical tests Gravels 3
2. Compression tests Cohesive soils and sand 12.5
Cohesive soils and 25-30
Comprehensive examination of construction
sands
3. material and borrow area soil including soil
stabilisation
Gravelly soil 50-100
While taking out disturbed soil samples, Standard Penetration Test may also be conducted to find
out the bearing capacity of the sub-soil at specified levels.
B-14.10.2 Undisturbed Soil Samples
The location of the bore-hole shall be as indicated on the drawing or given by the Engineer-in-
Charge.
The depth of the bore-hole shall be as indicated on the drawing or shall be governed by the criteria
given therein or as directed by the Engineer-in-Charge.
Samples shall be obtained in such a manner that their moisture content and structure do not get
altered. This may be ensured by careful protection and packing and by use of correctly designed
sampler.
Standard Penetration Test may have to be conducted in each case to obtain additional data as
directed by the Engineer-in-Charge. In soft clay, in-situ vane shear test as per IS: 4434 may have to
be conducted. Where all the three operations have to be carried out in one layer, the sequence shall
be undisturbed soil sampling followed by in-situ vane shear test, followed by Standard Penetration
Test.

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For compression test samples, a core of 40 mm. diameter and about 150 to 200 mm length may be
sufficient, but for other laboratory tests, a core of 100 mm diameter and 300 mm length shall be
taken as far as possible, unless otherwise specified by the Engineer-in-Charge.
The upper few millimeters of both types of sample shall be rejected as the soil at the bottom of the
bore hole usually gets disturbed by the boring tools.
B-14.10.3 Rock Samples
Disturbed samples:
The sludge from percussion borings or from rotary borings which have failed to yield a core, shall
be collected for a disturbed sample. It may be recovered from circulating water by settlement in a
trough.
Undisturbed samples:
Block samples taken from the rock formation shall be dressed to a size of about 90 x 75 x 50mm
In case of core samples, cores of rock shall be taken by means of rotary drills fitted with a coring
bit with core retainer, if warranted.
In case of rock at shallow depths which can be conveniently reached, test pits or trenches are the
most dependable and valuable methods since they permit a direct examination of the surface, the
weathered zone and presence of any discontinuities. It is also possible to take representative
samples for tests. For guidance, IS: 4453 may be referred to.

B-14.11 PROTECTION, HANDLING & LEBELLING OF SAMPLES

Care shall be taken in handling and labeling of samples so that they are received in a fit state for
examination and testing and can be correctly identified as coming from a specified trial pit or
boring.
The disturbed material in the upper end of the tube shall be completely removed before applying
wax for sealing. The length and type of sample so removed should be recorded.
The soil at the lower end of the tube shall be reamed to a distance of about 20 mm. After cleaning,
both ends shall be sealed with wax applied in a way that will prevent wax from entering the sample.
Wax used for sealing should not be heated to more than a few degrees above its melting
temperature. The empty space in the samplers, if any, should be filled with moist soil, saw dust,
etc., and the ends covered with tight fitting caps.
Labels giving the following information should be affixed to the tubes:
a) Tube number
b) Job designation
c) Sample location
d) Boring number
e) Sample number
f) Depth
g) Penetration
h) Gross recovery ratio
The tube and boring numbers should be marked in duplicate. Duplicate markings of the boring
number and sample number on a sheet which will not be affected by moisture should be enclosed
inside the tube.

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B-14.12 TESTS FOR EXPLORATION OF SHALLOW FOUNDATION OF BRIDGES
Test pits or trenches are the most dependable and valuable methods of exploration since they permit
direct visual examination and more reliably the type of soil and their stratification. This will also
allow in-situ tests like plate bearing tests, shear tests and uni-axial jacking tests, etc.
Tests shall be conducted on undisturbed samples, which may be obtained from open pits. The use
of Plate Load Test (as per IS: 1888) is considered desirable to ascertain the safe bearing pressure
and settlement characteristics. A few exploratory bore holes or soundings shall be made to
safeguard against presence of weak strata underlying the foundation. This shall extend to a depth of
about 1½ times the proposed width of foundation.
The laboratory results shall correlate with in-situ tests like Plate Load Tests and Penetration Test
results.

B-14.13 TESTS FOR EXPLORATION OF DEEP FOUNDATIONS OF BRIDGES

The tests to the conducted at various locations for properties of soil, etc., are different for cohesive
and cohesionless soils. These are enumerated below and shall be carried out, wherever practicable,
according to soil type.
B-14.13.1 For Cohesionless Soil
(a) Classification tests, density, etc.
(b) Field tests.
• Plate Load Test as per IS:1888.
• Dynamic Penetration test as per IS:2131 and Use of Dynamic Cone penetration
test as per IS:4968 (Part1 or Part 2) may be conducted where considered
appropriate.
(c) Laboratory tests: Shearing strength test – triaxial or box shear test – in case of the
possibility of rise of water table, the tests shall be done on saturated samples.
B-14.13.2 Cohesive Soils
(a) Classification tests, density, etc.
(b) Field tests.
• Plate Load Test.
• Unconfined Compression Test as per IS:2720 (Part 10).
• Vane Shear Test as per IS: 4434.
• Static Cone Penetration Test (IS:4968 Part 3).
(c) Laboratory tests: Shearing strength test – triaxial tests (IS:2720 Part 9), Consolidation
Test (IS:2720 Part 15).
Where dewatering is expected, samples may be tested for permeability (IS: 2720 Part 17).
The sub-surface exploration for bridge works can be divided into 3 zones:
(i) Between bed level and upto anticipated maximum scour depth (below H.F.L.)
(ii) From the maximum scour depth to the foundation level.
(iii) From foundation level to about 1½ times the width of the foundation below it.

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The sub-soil water shall be tested for chemical properties to ascertain the hazard of deterioration of
foundations. Where dewatering is expected to be required, permeability characteristics shall be
determined.
For the different zones categorized as above, the data required, such as soil classification, particle
size distribution, shearing strength characteristics, method of sampling disturbed and undisturbed
samples, testing, including particle size distribution, shear strength, unconfined compression test,
shall be complied with.

B-14.14 TESTING OF MATERIALS FOR GUIDE BUND & HIGH EMBANKMENTS

AND ITS FOUNDATION
The soil properties for the embankment foundation shall be as specified in particular specifications
and shall be got verified prior to construction operation. In case the actual soil properties do not
match the particular specification, then embankment design shall be revised.
Field investigation for the embankment material should be carried out to collect general
information as indicated in IRC: 75. For details refer to related Clause of embankment construction.
Field investigation for sub-soil strata shall consist of taking minimum two bore holes for each
approach to a bridge along centre line of the alignment at a distance of 50 m and 120 m behind the
abutment positions on both sides. The depth of bore holes below the ground level may ordinarily be
2.5 times the maximum height of the embankment subject to minimum depth of 20 m. Thin walled
sampling tubes of 100 mm internal diameter and 450 mm minimum length conforming of IS: 2132
shall be used for collecting undisturbed samples from bore-holes at an interval of 2.5 to 3.5 m.
Standard penetration test should be conducted immediately after undisturbed sample is collected.
In addition to the relevant identification tests, mentioned in IRC:75, it shall be necessary to conduct
some of the following tests on the undisturbed samples collected from the sub-strata. The choice of
test is primarily determined by the type of soil, type of stability analysis (vide Table B 14.14-1),
availability of apparatus and cost of investigation.
Table B 14.14-1: TABLE SHOWING SHEAR STRENGTH TESTS FOR STABILITY ANALYSIS
Sl. Stage in Life of Strength Shear Test Type of
No. Embankment Parameters Analysis
1 During construction or Cuu, φuu Unconsolidated un-drained tri-axial shear test Total stress
immediate post- on undisturbed samples and on compacted analysis
construction embankment materials.
2 –do- Su Unconfined Compression test in laboratory or -do-
Vane Shear test
3 During construction or C, φ’ Consolidated un-drained test with pore- Effective
immediate post- pressure measurement on as compacted soil stress
construction samples of embankment materials and on analysis
undisturbed samples
4 Long term stability C, φ’ -do- -do-

B-14.14.1 Laboratory Investigation of Embankment Material

The following tests should be conducted on representative samples of embankment material:
(i) Gradation Test (Sieve Analysis) : as per IS: 2720 (Part – IV).
(ii) Atterberg Limit Test : as per IS: 2720 (Part – V)
(iii) Standard Proctor Test : as per IS: 2720 (Part – VII)
(iv) Natural Moisture Content : as per IS: 2720 (Part – II)

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In addition to the above, there is need for shear strength tests on compacted of the fill material. For
this purpose, the relative compaction should be 95 per cent of the Standard Proctor maximum dry
density and moisture content, same as that likely to prevail in the embankment during the period
covered by the stability analysis or to be used in the field during construction. Undrained test shall
be run on cohesive soils and shear strength parameters should be ascertained for the ranges of
normal pressures which are likely to be experienced in the field. In cases where effective stress
analysis is required to be done, pore-pressure measurements should also be made during the
undrained tests and effective strength and pore-pressure parameters should be found out. For fill
material of cohesion less soils, a direct shear box test (IS: 2720-Part 13) may be conducted to
ascertain shear strength of soil.
The results of reconnaissance, field and laboratory investigations for embankments shall be
consolidated into a well-knit report. The record findings and recommendations, if any, may be
presented in the form of written test, graphs, figures and tables, as appropriate for different types of
data and findings.
Information and data to be contained in the report should include general location map, pertinent
geological information on reconnaissance observations, sub-soil profile (Fig. 2.1 of IRC: 75),
boring logs and summary of sub-soil properties (Fig. 2.2 of IRC:75), graphs and tables related to
laboratory investigations, results of borrow area investigations (Fig. 2.3 of IRC: 75) and
recommendations, if any.
The undisturbed samples shall be collected from each layer of sub-soil unless the stratum is such
that undisturbed samples cannot be collected using ordinary sampler. Where indicted by the
Engineer-in-Charge, undisturbed samples shall be collected using piston sampler or core cutter or
such special devices. In thick layers undisturbed samples shall be collected at 3 m interval.

B-14.15 MEASUREMENT FOR PAYMENT

In case of bridge and road structures, the work of boring and trial pits shall be considered as
incidental to the foundation works and nothing extra shall be paid unless otherwise specified in the
contract. In cases where it is specified to be paid separately, like Contract for soil investigation, the
work shall be measured in running meters for boring, in cubic meters for trial pits, in number of
samples for collection of disturbed and undisturbed samples and a number of tests for each type of
test.

B-15 PIPE CULVERTS

B-15.1 Scope
This work shall consist of furnishing and installing reinforced cement concrete pipes, of the type,
diameter and length required at the locations shown on the drawings or as ordered by the Engineer-
in-Charge and in accordance with the requirements of these Specifications.
B-15.2 Materials
All materials used in the construction of pipe culverts shall conform to the requirements of sections
B-11.1
Each consignment of cement concrete pipes shall be inspected, tested, if necessary, and approved
by the Engineer-in-Charge either at the place of manufacture or at the site before their incorporation
in the works.

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B-15.3 EXCAVATION FOR PIPE

The foundation bed for pipe culverts shall be excavated true to the lines and grades shown on the
drawings or as directed by the Engineer-in-Charge. The pipes shall be placed in shallow excavation
of the natural ground or in open trenches cut in existing embankments, taken down to levels as
shown on the drawings. In case of high embankments where the height of fill is more than three
times the external diameter of the pipe, the embankment shall first be built to an elevation above
the top of the pipe equal to the external diameter of the pipe, and to width on each side of the pipe
of not less than five times the diameters of pipe, after which a trench shall be excavated and the
pipe shall be laid.
Where trenching is involved, its width on either side of the pipe shall be a minimum of 150 mm or
one-fourth of the diameter of the pipe whichever is more and shall not be more than one-third the
diameter of the pipe. The sides of the trench shall be as nearly vertical as possible.
The pipe shall be placed where the ground for the foundation is reasonably firm. Installation of
pipes under existing bridges or culverts shall be avoided as far as possible. When during excavation
the material encountered is soft, spongy or other unstable soil, and unless other special construction
methods are called for on the drawings or in special provisions, such unsuitable material shall be
removed to such depth, width and length as directed by the Engineer. The excavation shall then be
backfilled with approved granular material which shall be properly shaped and thoroughly
compacted upto the specified level.
Where bed-rock or boulder strata are encountered, excavation shall be taken down to at least 200
mm below the bottom level of the pipe with prior permission of the Engineer-in-Charge and all
rock/boulders in this area be removed and the space filled with approved earth, free from stone or
fragmented material, shaped to the requirements and thoroughly compacted to provide adequate
support for the pipe.
Trenches shall be kept free from water until the pipes are installed and joints have hardened.

B-15.4 BEDDING FOR PIPES

The bedding surface shall provide a firm foundation of uniform density throughout the length of the
culvert, shall conform to the specified levels and grade, and shall be of one of the following two
types as specified on the drawings:
(i) First Class bedding:
Under first class bedding the pipe shall be evenly bedded on a continuous layer of
well compacted approved granular material, shaped concentrically to fit the lower
part of the pipe exterior for at least ten per cent of its overall height or as otherwise
shown on the drawings.
The bedding material shall be well graded sand or another granular material passing
5.6 mm sieve suitably compacted/rammed. The compacted thickness of the bedding
layer shall be as shown on the drawings and in no case shall it be less than 75 mm.
(ii) Concrete cradle bedding:
When indicated on the drawings or directed by the Engineer-in-Charge, the pipe shall
be bedded in a cradle contracture of concrete having a mix not leaner that M 15
conforming to Section B-11.4. The shape and dimensions of the cradle shall be as
indicated on the drawings. The pipes shall be laid on the concrete bedding before the
concrete has set.

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B-15.5 LAYING OF PIPES

No pipe shall be laid in position until the foundation has been approved by the Engineer. Where
two or more pipes are to be laid adjacent to each other, they shall be separated by a distance equal
to at least half the diameter of the pipe subject to a minimum of 450 mm.
The arrangement for lifting, loading and unloading concrete pipes form factory / yard and at site
shall be such that the pipes do not suffer any undue structural stain, any damage due to fall or
impact. The arrangement may be got approved by the Engineer-in-Charge.
Similarly, the arrangement for lowering the pipe in the bed shall be got approved by the Engineer-
in-Charge. It may be with tripod-pulley arrangement or simply by manual labour in a manner that
the pipe is placed in the proper position without damage.
The laying of pipes on the prepared foundation shall start from the outlet and proceed towards the
in let and be completed to the specified lines and grades. In case of use of pipes with bell-mouth,
the belled end shall face upstream. The pipes shall be fitted and matched so that when laid in work,
they form a culvert with a smooth uniform invert.
Any pipe found defective or damaged during laying shall be removed at the cost of the Contractor.

B-15.6 JOINTING
The pipes shall be jointed either by collar joint or by flush joint. In the former case, the collars shall
be of RCC 150 to 200 mm wide and having the same strength as the pipes to be joined. Caulking
space shall be between 13 and 20 mm according to the diameter of the pipe. Caulking material shall
be slightly wet mix of cement and sand in the ratio of 1:2 rammed with caulking irons. Before
caulking, the collar shall be so placed that its centre coincides with the joint and an even annular
space is left between the collar and the pipe.
Flush joint may be internal flush joint or external flush joint. In either case, the ends of the pipes
shall be specially shaped to form a self centering joint with a jointing space 13 mm wide. The
jointing space shall be filled with cement mortar, 1 cement to 2 sand, mixed sufficiently dry to
remain in position when forced with a trowel or rammer. Care shall be taken to fill all voids and
excess mortar shall be removed.
For joining pipe lines under light hydraulic pressure, the recess at the end of the pipe shall be filled
with jute braiding dipped in hot bitumen of other suitable approved compound. Pipes shall be so
joined that the bitumen ring of one pipe shall set into the recess of the next pipe. The ring shall be
thoroughly compressed by jacking or by any other suitable method.
All joints shall be made with care so that their interior surface is smooth and consistent with the
interior surface of the pipes. After finishing, the joint shall be kept covered and damp for at least
four days.

B-15.7 BACKFILLING
Trenches shall be backfilled immediately after the pipes have been laid and the joining material has
hardened. The backfill soil shall be clean, free from boulders, large roots, excessive amount of sods
or other vegetable matter, and lumps and shall be approved by the Engineer-in-Charge. Backfilling
upto 300 mm above the top of the pipe shall be carefully done and the soil thoroughly rammed,
tamped or vibrated in layers not exceeding 150 mm, particular care being taken to thoroughly
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consolidate the materials under the haunches of the pipe. Approved pneumatic or light mechanical
tamping equipment can be used.
Filling of the trench shall be carried out simultaneously on both sides of the pipe in such a manner
that unequal pressures do not occur.
In case of high embankment, after filling the trench upto the top of the pipe in the above said
manner, a loose fill of a depth equal to external diameter of the pipe shall be placed over the pipe
before further layers are added and compacted.

B-15.8 HEADWALLS AND OTHER ANCILLARY WORKS

Headwalls, wing wall, aprons and other ancillary works shall be constructed in accordance with the
details shown on the drawings or as directed by the Engineer-in-Charge. Masonry for the walls
shall conform to relevant clauses of the aforementioned specifications.

B-15.9 OPENING TO TRAFFIC

No traffic shall be permitted to cross the pipe line unless height of filling above the top of the pipe
line is at least 600 mm.

B-15.10 MEASUREMENT FOR PAYMENT

R.C.C pipe culverts shall be measured along their centre between the inlet and outlet ends in linear
meters.
Selected granular material and cement concrete for pipe bedding shall be measured as laid in cubic
meters. Ancillary works like headwalls, etc., shall be measured as provided for under the respective
Clauses.

B-16 BEARINGS
This work shall consists of furnishing and fixing bearings in position in accordance with details
shown on the drawing, to the requirements of these specifications or as directed by the Engineer-in-
Charge.
B-16.1 General
Bearing plates, bars, rockers, assemblies and other expansion or fixed devices shall be constructed
in accordance with the details shown on the drawings.
The bearings may either may supplied directly to the Engineer-in-Charge by the manufacturer to be
installed by the Contractor or the Contractor is to supply and install the bearings as part of the
contract. In the former case, the manufacturer shall be associated with the installation of bearings to
the full satisfaction of the Engineer-in-Charge, whereas in the latter case, the Contractor shall be
solely responsible for the satisfactory supply and installation of the bearing. In the detailed
description of the specification, a general reference shall be made to the Contractor or manufacturer
and the interpretation shall be as per terms of contract.
The Contractor shall exercise the utmost care in setting and fixing all bearings to their correct
positions and ensuring that uniformity is obtained on all bearing surfaces.
Bearings shall be handled with care and stored under cover.

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When bearing assemblies or plates are shown on the drawings to be placed (not embedded) directly
on concrete, the concrete bearing area shall be constructed slightly above grade (not exceeding 12
mm) and shall be finished by grinding.
It shall be ensured that the bearings are set truly level and in exact position as indicated on the
drawings as to have full and even bearing on the seats. The mortar pads (not exceeding 12 mm)
may even be made to meet with the requirements.
It shall be ensured that the bottoms of girders to be received on the bearings are plane at the
locations of these bearings and care shall be taken that the bearings are not displaced while placing
the girders.
M.S. bearing sliding on M.S. plates shall not be permitted. For sliding plate bearings stainless steel
surface sliding on stainless steel plate with mild steel matrix shall be used. The other option shall be
to provide PTFE surface sliding on stainless steel.
For detail specifications of different types of bridge bearings, such as Elastomeric bearing, Pot-
cum-PTFE bearing, etc please consult Section 2000 of MoRTH’s Specifications for Road & Bridge
Works (4th Revision).

B-17 EXPANSION JOINTS

This work shall consist of fabrication and placing of expansion joist as indicated on the drawing
and conforming to the specifications or as directed by the Engineer-in-Charge.
B-17.1 General
The expansion joints shall be designed and duly got approved by the Engineer-in-Charge. It shall
cater for expected movement and rotation of the structure at the joints and provide smooth riding
surface. It shall also be easy for inspection, maintenance and replacement.
Expansion joints shall be robust, durable, water-tight and replaceable. Site fabricated expansion
joints shall be prohibited. Expansion joints shall be obtained by the Engineer-in-Charge either
directly or through the Contractor from approved manufacturers and be of proven type.
For bridges with prestressed concrete superstructure, with individual span length more than 20 m or
built with innovative design/ construction elastomeric expansion joints of slab seal or strip seal
type shall be provided.
For slab seal type bridges of span less than 10 m, continuous surfacing may be provided across the
expansion gaps, supported on a 20 mm thick plate placed and fixed at the level of the deck slab.
For bridges other than those mentioned in para 3 above with spans above 10m., an alternative
specification of sliding steel plate or filled joints with copper plates may also be adopted if
approved by the Engineer-in-Charge, apart from elastomeric expansions joint of slab seal or strip
seal type.
Vehicular traffic shall not be allowed over expansion joints after its construction for such period as
may be determined by the Engineer-in-Charge.
Proprietary type deck joints offered by the Contractor in lieu of the type specified shall comply in
all respects with the manufacturer’s specification and meet the required range of movements and
rotations and be fit for the purpose of ensuring satisfactory long term performance in the bridge.

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Where alternative type proprietary deck joints are proposed by the Contractor, the following
information shall be provided.
(i) Name and location of the proposed manufacturer.
(ii) Dimensions and general details of the joint including material specifications, holding
down bolt or anchorage details and installation procedures.
(iii) Evidence of satisfactory performance under similar environmental conditions of
similar joints being produced by the manufacturer.
Any acceptance of alternative types will be at the sole discretion of the Engineer-in-Charge.
Such deck joints shall be installed in accordance with the manufacturer’s recommendations and to
the general requirements of this Specification.
No expansion joint shall be provided only for the width of the carriageway. It shall follow the
profile including the kerb and the footway and facia, if provided. The type of expansion joint may
be made different from that used for the carriageway expansion joint.
B-17.2 Requirements
The requirement criterion will be separately applicable for the expansion joint proper and the
transition zone of attachment to the deck.
There are two types of performance requirements for the expansion joints proper viz. from the
necessity of the bridge and from the road users e.g., man, animal and vehicle.
B-17.2.1 Performance requirement with respect to bridges
The expansion joint shall:
a) Withstand the imposed load from the live load and other sources,
b) Allow expansion and contraction movement due to temperature, creep, shrinkage, Pre-stressing
and structural deformation,
c) Permit relative rotation in elevation and plan due to the causes as noted above,
d) Be waterproof. Bridge deck expansion joint seals play a critical role in preventing the
degradation of the structural components of the bridge system. Without effective joint seals,
water passes through the bridge deck and works harmfully to corrode steel components and
cause deterioration of the concrete. Rain water gathers various corroding additives from the
atmosphere and also from the carriageway,
e) Ensure sealing. In case bridge deck joints are not sealed, apart from loss of waterproofing, grit
and other forms of road debris may enter the joint. Debris, when impacted with the joint can
seriously restrict the movement instead of facilitating the same. In the case of proprietary joints
being accepted for adoption, the sealing shall be as specified by them,
f) Ensure long life by being resistant to corrosion,
g) Be easy to install,
h) Be easy to maintain. Replaceability of expansion joint shall be one of the basic criteria for
selection of type of expansion joint,
i) Be resistant to the materials likely to collect/spill over the deck in its normal service,
B-17.2.2 Performance requirement with respect to user
The expansion joint shall:
a) Provide smooth continuity at the top of the deck for riding comfort,
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b) Be of skid resistant surface,
c) Be non-damaging to the rubber type,
d) Make minimum noise during vehicular crossing,
e) Ensure that animal paws and hooves should not get entangled where bridges are used by
animal drawn traffic,
f) Permit passing of bullock cart steel type for bridges where bullock carts ply,
g) Look good aesthetically.
B-17.2.3 Performance requirement for transition zone
It is the zone of connection of joint assembly and the adjoining deck.
The expansion joint shall:
a) Permit transfer of generated forces without distress, i.e., without getting uprooted. The purpose
will not be served if the bonding is with the wearing coat only. Anchorage must be provided
with the deck structural element,
b) Ensure that the surface in the transition zone stays undisturbed during long term service.
Generally the following types of expansion joints are provided in the bridge-deck:
1. Steel Plate Sliding Expansion Joints,
2. Filler Joints,
3. Elastomeric Slab Seal Expansion Joints,
4. Strip Seal Expansion Joint
For further details of the abovementioned types of expansion joints, please consult Section 2600 of
MoRTH’s Specifications for Road & Bridge Works (4th Revision).

B-18 TRAFFIC SIGNS & ROAD MARKINGS

The colour, configuration, size and location of all traffic signs for highways other than expressways
shall be in accordance with the Code of Practice for Road Signs, IRC:67 or as shown on the
drawings.
The signs shall be either reflectorised or non-reflectorised as shown on the drawings or as directed
by the Engineer-in-Charge. When they are of reflectorised type, they shall be of retro- reflectorised
type and made of encapsulated lens type reflective sheeting, fixed over aluminium sheeting as per
specifications.
In general, cautionary and mandatory signs shall be fabricated through process of screen printing.
In regard to informatory signs with inscriptions, either the message could be printed over the
reflective sheeting, or cut letters of non-reflective black sheeting used for the purpose which must
be bonded well on the base sheeting as directed by the Engineer-in-Charge.

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B-19 TRAFFIC SIGNS HAVING RETRO-REFLECTIVE SHEETING

B-19.1 General Requirements
The retro-reflective sheeting used on the sign shall consist of the white or coloured sheeting having
a smooth outer surface which has the property of retro-reflection over its entire surface. It shall be
weather resistant and show colour fastness. It shall be new and unused and shall show no evidence
of cracking, scaling, pitting, blistering, edge lifting or curling and shall have negligible shrinkage or
expansion. A certificate of having tested the sheeting for those properties in an unprotected outdoor
exposure facing the sun for two years and its having passed these tests shall be obtained from a
reputed laboratory, by the manufacturer of the sheeting.
The reflective sheeting shall be either Engineering Grade material with enclosed lens or of High
Intensity Grade with encapsulated lens. The type of the sheeting to be used would depend on the
type, functional hierarchy and importance of the road.
B-19.2 Engineering Grade Sheeting
This sheeting shall be of enclosed lens type consisting of microscopic lens elements embedded
beneath the surface of a smooth, flexible, transparent, water-proof plastic, resulting in a non-
exposed lens optical reflective system. The retro-reflective surface after cleaning with soap and
water and in dry condition shall have the minimum coefficient of retro-reflection as indicated in
Table B 19.2-1:
TABLE B 19.2-1: ACCEPTABLE MINIMUM COEFFICIENT OF RETRO-RELECTION FOR
ENGINEERING GRADE SHEETING (CANDELAS/LUX/SQ.METRE)
Observation Entrance
angle in angle in White Yellow Orange Green Red Blue
degree degree
0.2 -4 70 50 25 9 14.5 4
0.2 +30 30 22 7 3.5 6 1.7
0.5 -4 30 25 13.5 4.5 7.5 2
0.5 +30 15 13 4 2.2 3 0.8

When totally wet, the sheeting shall not show less than 90% of the value, of retro-reflection
indicated in Table above. At the end of 5 years, the sheeting shall retain at least 50% of its original
retro-reflectance.
B-19.3 High Intensity Grade Sheeting
This sheeting shall be of encapsulated lens type consisting of spherical glass lens, elements adhered
to a synthetic resin and encapsulated by a flexible, transparent water-proof plastic having a smooth
surface. The retro-reflective surface after cleaning with soap and water and in dry condition shall
have the minimum coefficient of retro-reflection as indicated in Table B 19.3-1.
When totally wet, the sheeting shall not show less than 90% of the value, of retro-reflection
indicated in Table above. At the end of 7 years, the sheeting shall retain at least 75% of its original
retro-reflectance.
TABLE B 19.3-1: ACCEPTABLE MINIMUM COEFFICIENT OF RETRO-RELECTION FOR
HIGH INTENSITY GRADE SHEETING (CANDELAS/LUX/SQ.METRE)
Observation Entrance angle (in Green /
White Yellow Orange Blue
angle(in degree) degree) Red
0.2 -4 250 170 100 45 20
0.2 +30 150 100 60 25 11
0.5 -4 95 62 30 15 7.5
0.5 +30 65 45 25 10 5

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B-19.4 Messages/ Borders
The messages (legends, letters, numerals, etc) and borders shall either be screen-printed or of cut-
outs. Screen printings shall be processed and finished with materials and in a manner specified by
the sheeting manufacturer. Cut-outs shall be of materials as specified by the sheeting manufacturer
and shall be bonded with the sheeting in the manner specified by the manufacture.
For screen-printed transparent coloured areas on white sheeting, the coefficient of retro-reflection
shall not be less than 50% of the values of corresponding colour in relevant Tables above.
Cut-out messages and borders, wherever used, shall be made out of retro-reflective sheeting (as per
Clause B-18.1.1.2 or B-18.1.1.3 as applicable), except those in black which shall be of non-
reflective sheeting.
B-19.5 Colour
Unless otherwise specified, general colour scheme shall be as stipulated in IS: 5. The colour shall
be durable and uniform in acceptable hue when viewed in day light or under normal headlights at
night.
B-19.6 Adhesives
The sheeting shall either have a pressure-sensitive adhesive of the aggressive-tack type requiring no
heat, solvent or other preparation for adhesion to a smooth clean surface, or a tack free adhesive
activated by heat, applied in a heat-vacuum applicator, in a manner recommended by the sheeting
manufacturer. The adhesive shall be protected by an easily removable liner and shall be suitable for
the type of material of the base plate used for the sign. The adhesive shall form a durable bond to
smooth, corrosion and weather resistant surface of the base plate such that it shall not be possible to
remove the sheeting from the sign base in one piece by use of sharp instrument.
B-19.7 Warranty and durability:
The Contractor shall obtain from the manufacturer a seven-year warranty for satisfactory field
performance including stipulated retro-reflectance of the retro-reflective sheeting of high intensity
grade and a five-year warranty for the adhesive sheeting of engineering grade, and submit the same
to the Engineer-in-Charge. In addition, a seven year and a five year warranty for satisfactory in-
field performance of the finished sign with retro-reflective sheeting of high intensity grade and
engineering grade respectively, inclusive of the screen printed or cut out letters/legends and their
bonding to the retro-reflective sheeting shall be obtained from the Contractor/supplier and passed
on to the Engineer-in-Charge. The Contractor/supplier shall also furnish a certification that the
signs and materials supplied against the assigned work meets all the stipulated requirements and
carry the stipulated warranty.
Processed and applied in accordance with recommended procedures, the reflective material shall be
weather resistant and after cleaning, shall show no appreciable discolouration, cracking, blistering
or dimensional change and shall not have less than 50% of the specified minimum reflective
intensity values in Tables above.
B-19.8 Measurements for Payment:
The measurement of standard cautionary, mandatory and information signs shall be in numbers of
different types of signs supplied and fixed, while for direction and place identification signs, these
shall be measured by area in square metres.

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B-20 ROAD MARKINGS

The colour, width and layout of road markings shall be in accordance with the Code of Practice for
Road Markings with Paints, IRC: 35, and as specified in the drawings or as directed by the
Engineer-in-Charge.
B-20.1 Materials
Road marking shall be of ordinary road marking paint, hot applied thermoplastic compound, or
reflectorised paint specified in the item and the material shall meet the requirements as specified
below.
B-20.2 Ordinary Road Marking Paint
Ordinary paint used for road marking shall conform to Grade 1 as per IS: 164. The road marking
shall preferably be laid with appropriate road marking machinery. Laying thickness of road
marking shall be as specified by the Engineer-in-Charge.
B-20.3 Hot Applied Thermoplastic Road Marking
B-20.3.1 General
(i) The work under this section consists of marking traffic stripes using a thermoplastic
compound meeting the requirements specified herein.
(ii) The thermoplastic compound shall be screeded/extruded on to the pavement surface in a
molten state by suitable machine capable of controlled preparation and laying with surface
application of glass beads at a specified rate. Upon cooling to ambient pavement
temperature, it shall produce an adhesive pavement marking of specified thickness and
width and capable of resisting deformation by traffic.
(iii) The colour of the compound shall be white or yellow (IS colour no. 356) as specified in the
drawings or as specified in the drawings or as directed by the Engineer-in-Charge.
(iv) Where the compound is to be applied to cement concrete pavement, a sealing primer as
recommended by the manufacturer, shall be applied to the pavement in advance of placing
of the stripes to ensure proper bonding of the compound. On new concrete surface any
laitance and/or curing compound shall be removed before the markings are applied.
B-20.3.2 Thermoplastic Material
The thermoplastic material shall be homogeneously composed of aggregate, pigment, resin and
glass reflectorising beads.
B-20.3.3 Composition
The pigment, beads, and aggregate shall be uniformly dispersed in the resin. The material shall be
free from all skins, dirt and foreign objects and shall comply with requirements indicated in Table
B 20.3-1:
TABLE B 20.3-1: PROPORTIONS OF CONSTITUENTS OF MARKING MATERIAL
(PERCENTAGE BY WEIGHT)
Component White Yellow
Binder 18 % (Minimum) 18 % (Minimum)
Glass beads 30 – 40% 30 – 40%
Titanium di-oxide 10% (Minimum) -
Calcium carbonate & inert fillers 42% (Maximum) See note
Yellow pigments - See note

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Note: Amount of yellow pigment, calcium carbonate and inert fillers shall be at the option of the manufacturer,
provided all other requirements of this Specification are met.
B-20.3.4 Reflectorising Glass Beads
This specification covers two types of glass beads to be used for the production of reflectorised
pavement markings.
Type 1 beads are those which are a constituent of the basic thermoplastic compound vide Table
above and Type 2 beads are those which are to be sprayed on the surface uniformly into a mono-
layer on to the hot paint in quick succession of the paint spraying operation. The glass beads shall
be applied at the rate of 250 gm/m2 area.
The glass beads shall be transparent, colourless and free from milkiness, dark particles and
excessive air inclusions. These shall conform to the requirements spelt out in “Specific
requirements” as given below.
Specific Requirements
A. Gradation: The glass beads shall meet the gradation requirements for the two types as given in
Table below.
TABLE B 20.3-1: GRADATION REQUIREMENTS FOR GLASS BEADS
Percent retained
Sieve size
Type - 1 Type - 2
1.18 mm 0 to 3 -
850 micron 5 to 20 0 to 5
600 micron - 5 to 20
425 micron 65 to 95 -
300 micron - 30 to 75
180 micron 0 to 10 10 to 30
Below 180 micron - 0 to 15

B. Roundness: The glass beads shall have a minimum of 70% true spheres.
C. Refractive Index: The glass beads shall have a minimum refractive index of 1.5.
D. Free flowing properties: The glass beads shall be of hard lumps and clusters and shall
dispense readily under any conditions suitable for paint stripping. They shall pass free flow-test.
B-20.3.5 Application properties of thermoplastic material
The thermoplastic material shall readily get screeded /extruded at temperatures specified by the
manufacturers for respective method of application to produce a line of specified thickness which
shall be continuous and uniform in shape having clear and sharp edges.
The material upon heating to application temperatures shall not exude fumes, which are toxic,
obnoxious or injurious to persons or property.
B-20.3.6 Properties of finished road marking
(a) The stripe shall not be slippery when wet.
(b) The marking shall not lift from the pavement in freezing weather.
(c) After application and proper drying, the stripe shall show no appreciable deformation or
discolouration under traffic and under road temperatures upto 600 C.

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(d) The marking shall not deteriorate by contact with sodium choride, calcium chloride or oil drippings
from traffic.
(e) The stripe or marking shall maintain its original dimensions and position. Cold ductility of the
material shall be such as to permit normal movement with the road surface without chopping or
cracking.
(f) The colour of yellow marking shall conform to IS Colour No. 356 as given in IS: 164.
B-20.3.7 Reflectorised Paint
Reflectorised paint, if used, shall conform to the specification by the manufacturers and approved
by the Engineer-in-Charge. Reflectorising glass beads for reflectorising paints where used shall
conform to the requirement of Clause B-18.2.3.3.
B-20.3.8 Measurements for Payment
The painted markings shall be measured in square metres of actual area marked (excluding the
gaps, if any).
In respect of markings like directional arrows and lettering, etc., the measurement shall be by
numbers.
For more details about Traffic Signs and Road Markings, one may consult the relevant Clauses of
the MoRTH’s Specification for Road & Bridge Works (4th Revision).

B-21 GEOSYNTHETICS FOR EMBANKMENT WORKS

B-21.1 Scope
This specification covers the various applications of Geosynthetic materials in road and bridge
works including supplying and laying.
‘Geosynthetic’ is a general classification for all synthetic materials used in Geotechnical
Engineering application. It includes geotextiles, geogrids, geonets, geomembranes and
geocomposites.
(i) Geotextile: Any permeable textile natural or synthetic, used with foundation, soil, rock,
earth, or any other geotechnical engineering related material. In the present chapter, it is
related to synthetic material only.
(ii) Geogrid: A deformed or non-deformed grid of polymeric material used primarily for
reinforcement purposes with foundation, soil, rock, earth, or any other geotechnical
engineering related material.
(iii) Geonets: These are net made of polymeric material used for drainage of foundation, soil,
rock, earth, or any other geotechnical engineering related material.
(iv) Geomembrane : An essentially impermeable membrane of polymeric material used for
foundation, soil, rock, earth, or any other geotechnical engineering related material. to
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(v) Geocomposites : A manufactured material using geotextiles, geogrids, geonets and/or
geomembranes in laminated or composite forms.
B-21.2 Application Areas
Some of the application areas for geotextiles and related materials and their functions are given
below in Table B 21.2-1:
TABLE B 21.2-1: APPLICATIONS AND FUNCTIONS OF GEOSYNTHETICS
Sl.No. Application Area Geosynthetics involved Functions for
Performance
1 Embankment for soft soils GT, GG R, S
2 Retaining walls GT, GG R
3 Drainage and Filtration GT F, S
4 Drainage-prefab, composite GC, GN D, F, S, B
5 Erosion Control rip rap GT F, S
6 Sediment control-silt fence GT B, R, S
7 Asphalt overlay GT, GC B, R, S
Note : GT – geotextile; GG – geogrid; GC – geocomposite; GN – geonet; S – separation;
R – reinforcement; F – filtration; D – drainage; B – barrier.

B-22 GEOSYNTHTICS FOR HIGHWAY PAVEMENTS

B-22.1 Scope
This work shall consist of laying geosynthetic materials over existing bituminous surface, including
preparation of surface and jointing, stitching or overlapping of geosynthetic fabric, etc, as part of
highway pavement strengthening in layers as shown on drawings.

B-22.2 Paving Fabrics

This work shall consist of furnishing and placing as asphalt/bitumen overlay textile (paving fabric)
beneath a pavement overlay or between pavement layers to provide a water resistant membrane and
crack retarding layer.

B-22.3 Material Requirements

Paving fabric: The paving fabric will be a non woven heat set material consisting of at least 85%
by weight polyolefins, polyesters or polyamides. The paving fabric shall be resistant to chemical
attack, rot and mildew and shall have no tears or defects which will adversely alter its physical
properties. The fabric shall be specifically designed for pavement application and be heat bonded
only on one side to reduce bleed-through of tack coat during installation. Heavy duty paving fabrics
should be used in areas experiencing unusually high impact forces or heavy loads such as airport
runways and taxiways.
Tack coat: The tack coat used to impregnate the fabric and bond the fabric to the pavement shall
be a paving grade bitumen of 80/100 penetration. A cationic emulsion may be used as approved by
the Engineer-in-Charge.

B-22.4 Construction and Installation Requirements

(a) Shipment and storage: The paving fabric shall be kept dry and wrapped such that it is
protected from the elements during shipping and storage. At no time shall the paving fabric
be exposed to ultraviolet light for a period exceeding 14 days. Paving fabric rolls shall be
stored in a manner which protects them from the elements.

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(b) Weather limitations: Minimum air and pavement temperature shall be at least 10oC for
placement of bitumen and shall be at least 15o C for placement of bitumen emulsion.
Neither bitumen tack coat nor paving fabric shall be placed when weather conditions, in the
opinion of the Engineer-in-Charge, are not suitable.
(c) Surface preparation: The pavement surface shall be thoroughly cleaned of all dirt, water,
and oil to the satisfaction of the Engineer-in-Charge. Cracks 3 mm wide or greater shall be
cleaned and filled with suitable bituminous material or by a method approved by the
Engineer-in-Charge. Crack filling material shall be allowed to cure prior to paving fabric
placement. Potholes and other pavement distress shall be repaired. Repairs shall be
performed as directed by the Engineer-in-Charge.
(d) Tack coat application: The tack coat shall be spread by means of a calibrated distributor
spray bar. Hand spraying and brush application may be used in location of fabric overlap.
Every effort shall be made to keep hand spraying to a minimum. The tack coat shall be
applied, uniformly to the prepared dry pavement surface at the rate of 1.0 kg/m2 or as
recommended by the paving fabric manufacturer and approved by the Engineer-in-Charge.
When using emulsions, the application rate must be increased as directed by the Engineer-
in-Charge to offset the water content of the emulsion. The temperature of the tack coat shall
be sufficiently high to permit a uniform spray pattern. For bitumen, the minimum
temperature shall be 1400C. To avoid damage to the fabric, distributor tank temperatures
shall not exceed 1600C. For bitumen emulsions, the distributor tank temperatures shall be
maintained between 550C and 700C.
(e) Paving fabric placement: The paving fabric shall be placed onto the tack coat using
mechanical or manual laydown equipment capable of providing a smooth installation with a
minimum amount of wrinkling or folding. The paving fabric shall be placed prior to the tack
coat cooling and loosing tackiness. Paving fabric shall not be installed in areas where the
overlay asphalt tapers to a thickness of less than 40 mm. Excess paving fabric which
extends beyond the edge of existing pavement or areas of tack coat application shall be
trimmed and removed. When bitumen emulsions are used, the emulsion shall be allowed to
cure properly such that essentially no water moisture remains prior to placing the paving
fabric. Wrinkles or folds in excess of 25 mm shall be slit and laid flat. All transverse joints
and slit folds or wrinkles shall be shingle-lapped in the direction of the paving operation. No
traffic except necessary construction equipment will be allowed to drive on the paving
fabric. Damaged fabric shall be removed and replaced with the same type of fabric.
Overlaps shall be shingle-lapped in the direction of paving. Additional tack coat shall be
placed between the overlap to satisfy saturation requirements of the fabric. Overlap shall be
sufficient to ensure full closure of the joint but not exceed 150 m.
(f) Overlay placement: Bituminous overlay construction shall closely follow fabric
placement. All areas in which paving fabric has been placed will be paved during the same
day. Excess tack coat can be removed by broadcasting hot mix or sand on the paving fabric.

C. PROCEDURES OF MEASUREMENT OF STONE AGGREGATES, BATS &

MISCELLANEOUS GRANULAR MATERIALS
C.1 Metal, Chips, Boulders, Bats, Sand, Surki, Lime:
(a) Unless specifically mentioned otherwise in the description of item itself, measurement for
supply and/or carriage shall be taken in stack and that as soon after the stacks are made as
possible. The height and the shape of the stacks shall be as per direction of the Engineer-in-
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Schedule : 2008-2009 General Specification
Charge but in no case shall the height of the stacks be less than the minimum stack height
for the concerned item. The payment shall be made on net quantity of materials after
deducting allowance for shrinkage and/or sinkage from the measured volume of fresh
stacks.
(b) If for any special reasons, as per provisions of any particular contract, final measurement
have to be taken at wagons at destination, before materials are unloaded, no deduction for
shrinkage shall be made.
(c) For conversion of brick materials from one form to another, 280 numbers of bricks shall be
considered to produce 1 (one) cubic meter of bats and 1.1 cubic meter of bats to produce 1
cubic meter of khoa or metal.
(d) For consolidation of stone, jhama metals and similar works, involving utilization of
materials already measured in stacks, the quantity of material actually consumed in such
works will be taken to be the same as the recorded quantities of stacks actually utilized,
after due deduction for sinkage and/or shrinkage is made.
TABLE C 1-1: MINIMUM STACK HEIGHT & ALLOWANCE FOR SINKAGE AND/OR SHRINKAGE
FOR DIFFERENT MATERIALS
Minimum stack Deduction in volume
Sl.
Materials height for sinkage and/or
No.
(cm) shrinkage
Stone metal, slag, ballast, chips, shingles/gravels,
1. 35 1/13
Moorum, bajree
Stone boulders of size below 15 cm., jhama metal,
2. 45 1/9
khoa or chips

3. Carried earth, rubbish (building or kiln) 35 1/9

Sand (necessary deduction for bulkage may be applied

3. 50 1/8
after deduction for sinkage/shrinkage)
4. Stone dust 50 1/8

Stone boulders of size 15 cm or above, jhama/brick

5. 55 1/7
bats

6. Lime 60 1/5

D. PAYMENT FOR CARRIAGE

No allowance shall be made for wastage of materials in transit and in re-stacking at different places,
except when such loss is due to special circumstances, which, in the opinion of the Engineer-in-
Charge, are beyond the control of the contractor.
The Schedule of Rate includes items for transportation by pucca road. Where any kutcha road is
involved, in part or in full, the length of the kutcha road stretches shall be increased by 50% to
consider those stretches as pucca road. Payment shall then be made on the basis of the equivalent
total pucca road length. This method will apply for road stretches including pucca & kutcha
stretches, irrespective of the kutcha portion within the route.

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General Specification Schedule of Rates : 2008-2009

For loading, unloading and stacking, payment for carriage by head load, involving a lead more than
30 m will be made only when the Engineer-in-Charge is satisfied that the trucks cannot approach
nearer.
When in the opinion of the Engineer-in-Charge, there are more than one possible route for the road
transport, payment shall be made on the basis of the cheapest of the possible alternatives,
irrespective of the route actually followed.
Carriage items shall be paid on net quantities arrived at after due allowance for sinkage and/or
shrinkage is made as per Table C 1-1.
Unless otherwise stipulated no carriage cost to any item of work will be admissible for materials
supplied to the contractor within a distance of 150 m of the nearest point of any work site. The
Engineer-in-Charge is the sole authority to define the boundaries of any worksite.

(J. Basu)
Superintending Engineer
Bridge Planning Circle
P. W. (Roads) Directorate
Bhabani Bhaban, Kolkata – 27

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