(JKR/SPI/1e88)

SECTION 4. FLEXIBLE PAVEMENT

&8e

4.1 UNBOUND PAVEMENT COURSES

4,1.1 Lower Subbasc
4.1.1,1 Dascription s4-1
4.r.L2 Materials s4-1
4.1.1.3 Coostruction Mcthods s4-1
4.r.2 Subbasc
4.1.2.1 Description s4-2.
4.1.L2 Materials s4-2
4.t2.3 Construction Methods s4-3
4.13 Gravel Surfacing
4.1.3.1 Description s4-3
4.t.3.2 Materials s4-3
4.1.3.3 Constru&ion Methods s4-4
4.1.4 Crushcd Aggregate Roadbasc
4.1.4.1 Description s4.5
4.t.4.2 Materials s4-5
4.1.4.3 Construction Methods s4.6
4.2 BITUMINOUS PAVEMEM COURSES
4.2.L Bitumen Prime Coat
4.2.1.1 Description s4.8
4,2.1.2 Materials s4.8
4.2.r3 Equipment s4-8
4.2.14 Construciton Methods s4-10
4.22 Bituminous Tack Coat
4.2.2.L Description s4-11
4.2.22 Materials s4-11
422,3 Equipment S,l - 11
4.2.2.4 Construction Methods s4-11
42.3 Bituminous Surfacc Dressing
4.2.1.1 Dcscription s4-12
4.2.3.2 Materials s4-12
4.233 Equipment s4-13
4.23.4 Construction Methods s4-15
4.2.4 Asphaltic Concrete
4.2.4.1 Description s4-20
s4-20
42.4.2
4.2.4.3
Matcrials
Asphaltic Concrcte Mix Desigt
y .22
4.2.4.4 Equipmcnt s4-26
4.L4.5 Construction Mcthods s4-30
4.2.5 Bituminous Macadam
42.5.L Description s4-36
4.25.2 Materials s4-5
4.25.3 Equipment s4-36
4.25.4 Construction Methods s4-36
4.3 SHOULDERS
43.r Description s4-39
4.3.2 Materials
4.3.2,L Earth Sboulders s4-39
4.3.2.2 Gravel Shoulders s4-39
4.3.3 Construction Methods s4-39
 (JKR/SPJ/1e88)

&se
{.4 HORIZONTAL ALIGNMENT, SURFACE LEVEIS AND
SURFACE REGUIJRITY OF PAVEMENT COURSES
4..1.1 Horizonral Alignment 54 . 41
4.4.2 Surface Courses
t*vels of pavement 54 - 41
4.4.3 Surface Regularity 54 . 4f
 (IKR/SPJ/1e88)

SECTION {. TLEXIBLE PAVEMENT

4.1 TJNBOUND PAVEMENT COURSES

4.1.1 L4wcr Subbase

4.1.1.1 Dcscrigtion

This work shall consist of furnishing placing compacting and shaping lorer
subbasc material on a prepared and iccepted subgrade in accordancc with tbis
Spccification and the linas, levels, grades, dimensions and cross-sections sho*'n
on the Drawinls and/or as required by thc S.O'

4.t.1.2 Materials

Iower subbase materiat shall be inorganic soil, sand, gravel, weathcred or

fragnentcd rock, or a mixture of any of these materialg essentially frce from
raictativc and oiher organic mattcr ind expansive clay minerals. lt shall ha\re
i"*imur particle size of ?5 mm or less, and shall haw a CBR value not less
"
than that shbwn on the Drawings w-hen compacted lo 95% of the maximum
dry density detcrmincd in thc B.S. 137 Compaction Tcst (4.5 kg rammer
mithod) and soaked fo. r 4 days under a surcharge of 45 kg.

4.r.r.3 Construction Mcthods

Prior io placing any lower subbase matcrial, the underlying. subgradc

500 mrn of thc subgrade) shall have becn sbaped and
(particulaity thc-top-accordance
-
courpacred in with the provisions of Sub'Sccrion 2.2.7.
Notwithstanding any earlicr approval of finished subgrade, any damage to or
detcrioration otlheiubgraAc ihatl bc nradc good to the satisfaction of thc S.O.
before lower subbase is constructed.

lower subbase shall be placcd orer thc full width of tlre formation to the
required thickness as sbovm on thc Drawings or dircaed by-the S'O. -in- one
layer or morc, cach layer not cxcceding a)0 mm cornpac{ed thiclness Whcre
two or morc laycrs ari required they shill be of approximately equd thickncss
and none shall bc less than 100 mm compactcd thickness

Each layer of lower subbase shall be processed as nccessary to. bring its
moisture contcnt to a uniform level throughout the materirfsuitablc for
oompaction, and shall then be compacted using suitable compaction equipment
by the S.O. to not less lhan 95Vo of the maximum dry density
diciermincd'in thc B.S. 137/ Compaction Test (4'5 kg rammcr method).
"pprbved
Compaction shatl bc carried out in a longtudinat direction along the roadbcd
and sialt generally bcgin at the outer edge and progress uniformly towards the
oti each side-in such a manner thaf each section receives equal
"ro*n
compactive effort, all to thc satisfaction of the S'O.

The lower subbasc shall be finished in a neat and workmanlike manner, and
shall have an average thickness over any 100 metre length not-le-ss lhan thE
required thickness.- The top surfacc of thc lower subbase shall have the
rcquired shape, supcrclcvatibn, lcvels and grades, and shall be everywhere
within the toicrances specified in Sub'Section 4.4.

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 (JKR/SPJ/1e88)

4.r.2 Subbase

4.t.2.1 Desgiption

This-worl shall consist of furnishing placing compacting and shaping subbasc

m.a1erlal on a prepared and accepted iubgride or iower Jubbasc in aiordancc
with this specification and thc lines, lcvels" grades, dimensions and crocs-
sccuons snown or rne rlrawmgs and/or as reguired by the S.O.

4.1.2.2 Materi?ls

subbase material shall be a natural or prepared aggregate comprising crushed

rock, wealhered-or fragmented rock, grivcl or-iruihed grai.e[ sin4 or a
mixture o.f agy of rbese matgrials. It shall have a small pr6portion of ptastic
or non'plastic fines and shall be essentially free from iegitative and-other
organic matter, expansive clay minerals and'lumps of clay, -The materiat shall
conform to the following physical and mechanical quatity requircments :-

i) the liquid limit sha[ be not more than 2SVo;

ii) the plasticity index shall be not more than 6;

iiD the aggregate crushing.vatue when testcd in accordance with M,S. 30

shall be not more than 35;

t") unless.otherwisc specified on the Drawings or directed by thc S.O, thc

material shall have a CBR value of 30 or more whcn 'compacted to
95Vo of the maximum dry density determined in thc B.S. 137/
Compaction Test _(45 kg rammer rneihody and soaked for 4 dayc undcr
a surcharge of 4.5 kg;

v) the gradation shall conform to one of the envelopes showu in

-
Table 4.1 with thc fraction passing the B.S. 25 um sieve not grcater
thanl/3 of the fraction passing t[e B.S. 425 um sieve.

TABLE 4.I . GRADATION LIMTTS FOR SUBBASE MATERIAL

B.S. Sieve Vo Passing By Weight

Size

A B c D E F

50.0 mm 100 100

25.0 mm 't9- 95 100 r00 100 100
9.5 mm 30- 65 4- 75 50.85 60 - 100
4.75 mm 25- 55 $-@ 35- 65 50- 85 55 - 100 70 - 100
2.00 mm 15- 40 m- 45 25- 50 n- 70 ,|() - 100 55- 1@
4E um E- 20 15- 30 15- 30 25- 45 m-fi n- 70
75 um 2-8 5-m 5-n 5-n 6-m E- 25

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 (JKR/SPJ/1e88)

4.1.2.3 Construction Mcthods

Prior to placing any subbasc matcrial, the undcrlying subgradc (particularly the
top 3m mm of thc subgrade) or lowcr subbasc shall havc bcen shapcd and
compacted in accordance with the prwisions of Sub-Section 2.2.7 or Sub-
Section4,1.1.3 as appropriatc. Notwithstanding any carlier approval oflinished
subgrade orlower subba.se, any damagc to or dcterioration of thc subgrade or
lower subbase shall be made good to the satisfaction of thc S.O, bcftrre subbase
is conslructed.

Subbasc shall be placed with eguipment approved by the S.O. over the full
width of thc frrrmation to thc required thickncss as shown on the Drawings or
directed by the S.O. in one layer or more, each laycr not exceeding 2(IJ mm
compacted lhickncss. Where two or more layers arc rcquired they shall bc of
approximately equal thickncss and none shall bc lcss than 1fl) mm compacted
tbiclness.

Each laycr ol subbase shall be processcd as neccssary to bring its moisture

content to a uniform lcvel throughout thc matcrial suitablc for compaction, and
shall then be compactcd using suitable compaction cquipmcnt approvcd by the
S,Cr. to not lcss than 95% of lhc maximum dry dcnsity dctcrmincd in the B.S.
1377 Compaction Test (4.5 kg rammcr method). Compaction shall bc carried
out in a longitudinal dircction along the carriageway, and shall generally begin
at thc outcr cdge and progrcss uniformly towards the centrc on cach side,
ercept on supcrelevated curves where rolling shall begin at thc lower edge and
progress uniformly towards the highcr edgc. ln all cascs compaction shall be
carrled out in such a rnanner that each section receivds cqual compactivc efforl,
all to thc satisfaction of the S.O.

Throughout the placing adjustment of moisturc content and compaction of

subbase material, care shall be taken to maintain a uniform gradation of thc
matcrial and pr€vent its separation into coarse and fine parts, all to the
satisfaction of the S.O.

T'he subbasc shall be linished in a neat and workmanlike manner; its width
shall be everyrvhere at least that specitied or shown on the Drawings on both
sides of the centre-line; and its average thickness over any lfl) metre length
shatl be not less than thc required thickness. The top surface of thc subbasc
shall ha're thc required shape, superelcvation, levcls and gradcs, and shall bc
cverywhere within the tolerances specilied in Sub-Section 4.4.

4.1.3 Gravel Surfacing

4.1.3.1 Descrigtion

This worl shall consist of furnishing placing compacting and shaping gravel
surfacing matcrial on a prepared and accepted subgrade or lower subbase in
accorda;ce with this Specification and the lines, lcvels, grades, dimensions and
cross-sections shown on the Drawings and/or as required by the S.O'

4.L3.2 Materials

Cravel surfacing material shall be a natural or prcparcd soil-aggregate mixture

comprising gravel and sand size particles togcthcr with a small proportion of
plastic fines, and shall be essentially frce from vegctativc and other organic
matter, expansive ctay minerals and lumps of clay. Thc matcrial shall conform
to the followirig phpical and mechanical quality requirements l-

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 (JKR/SPJ/re88)

i) the liquid limit shall bc nor more than 35Vo;

iD the plasticity index shall be in the range 4 to l0;

iii) the aggregate crushing value when tested in accordancc with M.S. 3O
shall be not more than 35;

iv) the gadation shall conform to one of the envclopes shown in

Table 4.2 with the fraction passing the B.S.75 um sieve not greater
lhan 2/3 of the fraction passing the B.S. 425 um sieve.

TABLE 4.2 . GRADATION LIMITS FOR GRAVEL SURFACING

B.S. Sieve Vo Passing By Weight

Size

A B c D

37.5 mm 100 tm 100 100

12.5 mm 45- 15 55- 85 ri - roo
4.75 mm 30- 60 35- 65 50- 85 55- 90
2.fi) mm m- 45 25- 50 q- 70 4- 70
A5 um 15- 30 15- 30 25- 45 n- 50
75 um 8- 20 8- 2t 8-n 8- 25

Material with a maximum particlc size of 37.5 mm, while otherwise not
conforming to the gradation spccification but satisfying the other requirements,
shall be acccptable provided that it shall have a CBR value of30 or more when
compacted to 95Vo oI the maximum dry density determincd in the B.S. l3Z
Conpaction- Test (4.5 kg ramrner method) and soaked for 4 days under a
surcharge of 4.5 kg.

4.t3.3 Construction Methods

Prior. to placing any gravel surfacing materiat, the underlying subgrade

(particularly the top 300 mm of the subgrade) or lower subbase shal have-been
shaped and compacted in accordance with the provisions of Sub-Section 2.2.7
or Sub-Section 4-1.1,3 as appropriatc. Notwithstanding any earlier approvat of
finisbed subgrade or lower subbasc, any damage to or deterioration of the
subgrade or lowcr subbase shall be made good io the satisfaction of the S.O.
before gravel surfacing is constructed.

Grarrel surfacjng sball be placed to the required width and thickness as shown
on the .Drawings or directed by the S.O. in one layer or more, each layer not
exceeding_ 200 _mm compacted thickncss. Whcre two or more layirs arc
reguired they shall be of approximately equal thickness and none shait be less
than l(tr mm compacted thickness.

Each layer of gravel surfacing shall be processcd as neccssary to bring its

moisture content to a uniform lcvel throughout the materiai suitablJ for
compaction, and shall then be compacted using suitable compaction equipment

s44
 (!KR/SPU1e88)

aDDroved bv the S.O. to not less than 95Vo of the maximum dry density
dliermined'in the B.S. 13?7 Compaction Test (4.5 kg rammer nrethodJ'
Compaction shall be carried out in a longitudinal dircction dolg th€
and shalt generally begin at the outer edge and progess uniformly
cairiigc*ay,'cenrre
io*-i. the oniach side, eicept on supcrelevated curws wherc rolling
in.ff U"gin at the lower edge and progress qnifon-nly towards thc higler cdge'
in ail caicr compaction shill be carriCd out in such a mann€r that each Ecdion
rcceivcs equal cbmpactive effort, all to the satisfaction of the S.O.

Throuehout the placins. adiustment of moisture content and compaction of

uniform gradation
-aueliurf"cins iateriii, caie shall be tahen to maintain afine parts, dl to thc
[fili,"r.ri.i"nd prevcnr its separation into coarsc and
satisfaction of the S.O.

The cravel surfacing shall be frnished in a neat and workmanlikc manner; its
widtlishall bc eveqivhere at least that specified or shown on the Drawings on
both sides of the ientrcJine; and its average thickncss o/er any 100 mctrc
linllth shall be not less than tire required thickness and its minimum thictness
11 fny p6int shall be not less than thc rcquired thickness minus Z)
mm' Thc
ioo ititfu." of the glavel surfacing- shall have the requircd slrapc,
,uLJ"r"tion. tevcls an-rl grades, and shall be everywhere within 10 mm of thc
t"iuii.O ptane or such hi[-her, apptoximately parallel plane, as the S'O' shall
approve.

4.t.4 Crushed Agrcgate Roadbase

4.1.4.1 Descrigtion

This work shall consist of furnishing placing compdcting and shaping crushcd
assJeaatc roadbase material on a prcpared and acccpted slbgra-dc or -lower
ffiU"i" or subbase in accordance ulith-this Specilication and thc lincq leve\
.ua"i. Ai^"ntions and cos-sections shown on the Drawings and/or as
iequired by the S.O.

4.L.4.2 Materials

Crushed aggegate roadbasc material shall be crushed r9c!r, o1 crushed gravel

;;;;*ffi oFcrushed and natural aggregates, which is har4 durable, clean
and essentially free from clay and other deleterious malerials'

The materiat shall conform to the following phpical and mcchanical quality
requiremcnts :-

i) the plasticity indcx shall be not more than 6;

iD the aggregate crushing value whcn tested in accordance with M'S' 30

shall bc not more than 30;

iir) the flakiness index whcn tested in accordance with Ms. 30 shall bc
not more than 30;

iv)
- not less than 80% of particles retained on the BS. 4.75 mm sieve shall
have at least one fractuted face;

v\' thc weichtcd averase loss of wcight in the sodium sulphatc rcundncss
l.rt (5 {ctcs) when*tested in accordance with AASHTO Tc'st Method
T 104 shall bc not more than lZ%i

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 (JKR/SPJ/1e88)

vi) the matcrial shall have a CBR valuo of not less than 80 whcn
compacted to 957o of the maximum dry density determined in thc B.S.
137? Compaction Test (4.5 kg rammer method) and soated for 4 dayc
undcr a surcbarge of 4.5 kg;

vii) the gradation shall comply with the envelope shorva in Table 43 for
the type spccified.

TABLE,IS - GRADATION LTMITS FOR

CRUSHED AGGREGATE ROADBASE

B.S. Sierae 7o Passing By Wcight

Siz.e

Type I Type II

50.0 mm 100 100

37.5 mm 95-lm E5 - 100
?3.0 mm 70-lm
?n.O mm @- 80 60.90
10.0 mm 40- fs ,10 . 65
5.0 mm
2.% mm
25- n n- 55
15- 30
2.@ mm
600 um 8- 22
n- q
425 um 10- /5
o- 6 2- l0

1.1.4.3 Construction Mcthods

Prior to placing any crushcd aggrcgate roadbasc matcrial, thc undcrlying

gubgrade or lower. srtrbase or subbase shall havc becn shaped and compaoeJ
in accordance with the provisions of lhe appropriats Scctiorr of this
Specification. Notwithstanding any earlicr appiivai of finished subgrade or
lower subbase or subbase, ary damagc to or ditcrioration ofthe sutrlradc or
lower subbase or subbase shall be made good to the satisfaction offhe S.O.
bcfore crushed aggregate roadhase is conitructed.

Crushed aggrcgate roadbasc shall bc placcd to thc rcquircd width and thickncss
as shown on thc_Drawings or dirccrcd by the S.0, in one laycr or morc, cach
laycr not excecding- 200_ mm-compaclcd thickncss. Whcre two or morc laycrs
arc requircd they shall bc of approximarely equal thickness and none ihalt
-Sprcading
bc lcss .than lfi)
mm compactcd thickncss.. shall hc doric by a
mechanical spreader approved by thc S.O, or,- if appiovcd by the S.O.,'by
motor gradcr.

Prior to spreading, crushcd aggregate roadbase shall bc processed as nccessary

to bring its moisturc conlcnt to a uniform lcvel throughout the matcrial suitabti
for compaction, sprcad matcrial shall bc maintainid at lhe corrcct moisture
contcnt for propcr compaction by sprinkling with watcr oi dryrng as may bc
necessary and shall bc compacted using -suitablc compactiori equipment

s4- 6
 (JKR/SPJ/1e88)

approved by the S.O. to not less than 95Vo of the maximum dry density
determincd in the B.S. 1377 Compaction Test (45 kg rammer method).

Compaction shall be carried out io a longitudinal direction along the

carriigeway, and shall gcnerally begin at the outer edge and progress uniformly
towards lhc centre on iach side, cxcept on superelevated curves wherc rolling
shatl begin at the lower edge and progress uniformly tonards thc higber edgc'
In all cases coinpaction shirll be carried out in such a manner that cach section
receives cqual compactivc effort, all to the satisfaction of the S.O.

Throughout thc placing adjustment of moisture content and comPaction of

cushed aggregate roadbase material, care shall be taten to maintain a uniform
gadation of tfie material and prevent its separation into coarsc and finc partq
all to thc sritisfacrion of the S.O.

The crushed agSregate roadbase shall bc frnished in a neat and workmanlike

manner; ils widih Jtratt Uc everywbere at least that specified ot shown on the
Drawings on both sides of the centre-line; and its average thickness over any
lm rnetrc length shall be not less than the required thickness. Thc top surface
of the crushcd aggregate roadbase shall have the required shape,
superclcvation, levcls and grades, and shall bc everywhere within the loleranccs
specified in Sub-Section 4.4.2.

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 (JKR/SPJ/1e88)

4.2 BITUMINOUS PAVEMENT COURSES

4.?..1 Bitumgn Primc Coat

4.2.1.r Descriolion

This work shall consist of the carcful and thorough cleaning of the surface of
a pr-cpared and_ accepted crushed aggregate roadbase, and the furnishing and
applicatitrn to tte cleaned roadbase surface of a bituminous priming materiat,
all in accordance with this Spccification .and the lines, dimensions?nd bross-
sections shown on the Drawings and/or as rcquired by the S,O.

4.2.t.2 Materials

The bituminous priming matcrial shall be eithcr cut-back bitumen or bitumen

emulsion as stated in the Bill of Quanrities.

Cut-back bitumen shall bc grade RC-70 or MC-70 conforming to the

requiremcnts of M.S. 159.

Bitumen crnulsion shall be slow setting, grade SS-1 or SS-lK, conforming to

thc requircmcnts of M.S. 161, as appropriate to the type of roadbasc material
to be primcd and approvcd by thc S.O.

4.2.1.3 Eouinmcnt

Thc cquiprnc,nt used by the Conlractor shall include a power broom, a

compresscd ait blower, a sclf-propclled pressure distributor for bituminous
material, and as necessary equipmcnt for storing and hcating bituminous
material.

(a) Po*'u Broonr

The powcr broom shall be a rotary type specifically dcsigned for sweeping road
surfaces, and shall be approved by the S.O.

(b) Conrpressed Air Blower

Thc compresscd air blower shall comprise a portable air compressor of 3
cu.m/min. in capacity at 0.7 N/sq.mm dclivcry pressure wilh a suitable hose
and nozzlc for blowing clcan a road surlace aftcr powcr brooming and shall
be approvctl by thc S.O.

(c) I'rcssure Distihutor ftr Bitutttinous Malerial

Thc-distributor shall be a purposu built modcl of recognised manufacture and

shall bc approvcd by thc S.O. lr shall conform to the iequirements describcd
hcreundcr.

Thc di.striburor shall havc a suirablc capacity and shall be equipped with a gas
or oil. fircd.hcaring sysrcm capablc of hearing a full chargC bf bituminous
matcrial ro lti0 "(1. Thc hcating systcm shall bc such lhat overheating of the
bituminous matcrial will no( occur. and shall bc of a typc in which ftamis from
the burncr do not comc into dircct contact with ihe casing of thc tank
containing thc bituminous malcrial. Thc tank shall be insulatcd in such a
manner that when filled with bituminous material al lg0 oC and not heatcd.

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 (JKR/SPJ/re88)

the drop itr tempcrature shall bc lcss lhan 3 oC per bour. A thermometcr
sball bc provided to neasure contiouously the temp€rature of thc bituninors
material in the tank and shall be so arranged that thc highcst tcmpcraturc ia
tbc tank is measured. Tbe tank sball be fitted with al accuratcly calib,ratcd
diFtick or cont€nts gauge, and thc pipc for filling thc tank shdl bc littcd sith
an easily replaceable filter.

The distributor shall run on pneumatic tyred whecls ofsuch width and numbcr
tbat thc load produccd on the road surface whcn the vchiclc is fully chargcd
shall not excrcd|o tg/mm of tyrc width. The vehicle shall bc cquippcd *ith
a 'fifth whecl' tachcometer systen to accurately measurc its forvard spccd
during spraying opcrations.

The distributor shall bc equipped with a fitll clrculation t)?o spray bar wilh
aozzles from which the bituminous naterial is sprayed on to thc road surfacc
uniformly over thc full spraying width. Tbe spraying txidth shall be ndablc
in increments of not more than l(tr mm up to a maximum of 5O mctrcs. Tbc
spraying pump shall bc driven by a separat€ po*cr unit and shall bc cquippc/
with an accurate prcssurc gaugc and an accuratc flor ratc gauge or mcler. On
thc suction side tbc pump shall be fitted with an easily rcplaceable filto. Thc
spray bar and pump shall bc so dasigned that bitumhous matcrial at cr"D
tcmperature afld uniform pressure may be spraycd uniformly owr thc spraying
width at controlled ratcs in the rangc 0.25 to 8.0 litras/sg.u Nt normal
distributor opcrating spceds, such that deviation from thc prescribed ratc of
application shall not excr"t LO%.

Thc distributor shatl ba equipped with a hand spraying rystem.

The meters for tbe 'fifth whecl' tachometcr system and thc bituminous nralcrial
purnping flow ratc, pumping pressurc and tcrnperature shall bc locatcd in sucb
a tranncr tbat the vehiclc drirrer can casily rcad lhorn uAib opcrrting thc
distributor, Thc sprai bar shall bc controlled by a scconil opcr+or riding at
thc rear of the vehiclc in such a position that all thc dischargc sprs'6 aro in his
good view

All measuring equipmcnt on the distributor shall have bccn rcccntly calibratd
and accurate and satisfactory records of thc calibrations shall bc submittcd to
thc S.O. If in the coursc of the work the ratcs of application of bituminorrs
material arc fouod to be inaccurate, the distributor sball be withdrawn from
thc Works and recalibrated to thc satisfaction of the S,O. bcforc bcing roturncd
to scrvicc.

The S,O. may requirc suci performancc tests as hc considers rccassary to

chcct that the distributor is operating satisfactorily. As dircctcd by tho S.O"
the Contraclor shall make thc dhtributor and its cquipncnt arnrilablc for such
tcsts and shall supply all necessary assistancc, materials, toolq testing apparatug
etc, all at the Contractor's own expense.

(d) Swoge and Heoting Facilitics lu Binminans Matcrial

Tank for storagc of bituminous material shall havc a capacity suitcd to thc
proposed rate of utilisation of the material and the method and frcqucncy of
its dclivery to the Workq all to the satisfaction of the S.O. Tlrc tants and
where necessary, barret decanten shall be equipped with beating syrtcrrs which
provide for effcaivc and positirac control of thc tcmp€raturc of thc bituminous
matcrial at all timcs up to thc temp€rature required for utilisatioo. Ttc
method of heating shall be sucb thal ncithcr flamcs nor tbc produds of

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 (JKR/SPJ/1e88)

combustion shall comc into dircct contact with the biturninous material or the
casing of its immediate container, and such that no portion of the bituminous
material shall be subject to overheating.

4.2.1.4 Construction Methods

(a) General Conditions

Bitumen prime coat work shall only be carried out in dry, warm weather when
the surface to be treated is essentially dry.

(b) Surface Prepatation and Cleaning

Prior to applying the prime coat, the crushed aggegate roadbase sball have
been shaped and compacted in accordance with the provisions of Sub-Section
4.1.4.3. Notwithstanding any earlier approval of linishcd crushed aggregate
roadbasc, any damage to or deterioration of the roadbase shall be made good
to the satisfaction of the S.O. before prime coat'is applied.

Immediately prior to applying the bituminous material, the full width of the
surface to be treated shall be swepf using a power broom followed by a
compressed air blower and, if necessary scraped using hand tools to remove
all dirt, dust and other objectionable material, all to the satisfaction ofthe S.O.

(c) Application of Birunrinous Moteial

The bituminous priming material shall be sprayed on to the cleaned roadbase

surface by means of a pressure distributor. Any areas inaccessible to the
distributor spray bar shall be treated using the distributor's hand sprafng
system. The rate or rates of application shall be as directed by the S.O. based
on the resuhs of test applications, but shall usually be in the range 0,5 to 1.0
litre/sq.m. The temperature of cut-back bitumen shall be maintained in the
range 50 oC to 70 oC during spraying operations. For bitumen emulsions, the
spraying temperature shall be in the range 25 oC to 45 oC.

If necessary, in order to prcvent the bituminous material from flowing on the

sprayed surface, the prescribed prime coat shall be applied in two separate
spraying operations. Where the condition of the trcated surface indicates that
it is necessary bituminous material additional to that prescribed shall bc
applied as tbe S.O. shall direct.

Prime coat shall bc distributed uniformly ovcr the surface to be treatcd without
streaking; thc quantities apptied shall not deviate by more than 107a from those
prescribed. Arcas with insufficicnt bituminous matcrial .shall be resprayed as
necessary to make up the dcficiency, all to the satisfaction of the S.O.

The surfacos o[structures, road furniturc and trees adjacent to the areas being
spraycd shall bc protected in such a manncr as to prevcnt thcir being spattered
or marred by bituminous material. Bituminous material shall not be discharged
into road drains, guttcrs, ctc.

(d) Cuing and Opcning to Traffic

Prime coat shall normally be lcft undisturbed for at lcast 24 hours after
application and shall not be opcned to rraffic unril, in the opinion of the S.O.,
it has penetra(ed thc roadbasc and cured sufficiently so that it will not be
picked up by the whcels of vehiclcs.

s4- l0
 (rKR/SPJ/reE8)

The Contractor shall maintain the prime coat, all to thc satisfaction of the S,O.,
until the ovcrlying palcment course is constructed which shall not bc within
24 hours aftcr the application of the bituminous priming material nor u'ithin
such longer pcriod as is requird in the opinion of the S.O., for tbc primc coat
to achieve ma$mum penetration of the roadbase and bccome fully cured.

4.2.2 Bituminous Tack Coat

4.2.2.r Description

this work shall consist of the careful and thorough cleaning of thc surfacs of
a prepared and acceptcd bituminous or bitumen prirned pavcment coursc, and
thl furnishing and application to thc clcaned surface ofa bituminous tacl coat
prior to thc loratruction of an overlying bituminous pavement coursc, all in
iccordancc with this Specilication and the lines, dimensions and cross'sections
shown on the Drawings and/or as requircd by the S.O.

4.2.L2 Materials

Bituminous tack coat material shall be rapid setting bitumen emulsion of gade
RS-l or RS-IK conforrning to thc requirements of M.S. 161.

4.LL3 Equipmcnt

The equipment shall be as spccilicd in Sub-Section 4.2.1.3.

422.4 Construction Methods

(") Cenerol Conditio,rs

Bituminous tack coat shall only be applied to a clean, dry bituminous or

bitumen primcd surface.

Bituminous tack coat shall only be applicd as far in advance of the consttuction
of the overlying bituminous pavcment coursc as is necessary to achieve a
satisfactory degree of tackiness bcfore the overlfng material is placed, all to
the satisfaction of the S.O.

(b) Su(ace Preparotion and Cleaning

Prior to applying bituminous tack coat, the surlace to bc treated shall have
been prepiiei in accordancc with the appropriate Scctions of this Specilication.
Notwithsianding any earlier approval of this surface, any damagc to it or
deterioration of il shall bc made good before tack coat is applied.

lmmediatcly prior to applying bituminous tack coat, the full width of the
surfacc ttt bo troated shall bc swcpt using a Powcr broom followed by a
compressed air blower, and if necessary scra;rd using hand toolsr to rcmorc
alt dirt, dust and other objectionablc matcrial, all to the satisfaction ofthc S.O.

(c) Application of Binminous Matuial

The bituminous tack coat shall bc sprayed or to thc cleancd biluminous or

bitumen primcd surfacc by mcans of a prcssure distributor. Any arcas
inaccessiblc to the distributor spray bat shall bc treated using thc distributor's
hand spraying systcm. The rate or rates of application shall bc as dircctcd by
th€ S.O. baseOon the rcsults of test applications. but shall usually bc in thc

s+11
 (JKR/SPJ/1e88)

range 0.25 to 0.55 litres/sq.m. The temperature of the bituminous material

shall bc maintained in the range 25 oC to 45 oC during spraying operations,

Tack coat shall be distributed uniformly over the surface to be treated without
streaking; the quantities applied shall not deviate by more than 107o from
those prescribed. Areas with bituminous ma(erial in excess of these limits shall
have the excess removed at the Contractor's expgnse, and areas with insufficient
bituminous material shall be resprayed as necessary to makc up the deficiency,
.all to the satisfaction of the S.O.

The surfaces of structures, road furniture and trees adjacent to the arcas being
sprayed shall be protected in such a manner as to prevent their being spattered
or marred by bituminous material. Bituminous material shall not be discharged
into road drains, guttcrs, etc.

Traffic shall be kept off the tack coat at aU timeg and the Contractor shall
maintain the tack coat, all to the satisfaction of the S.O., until the overlying
pavement course is constructed.

4,2.3 Bituminous Surfuce Dressing

4.2.3.1 Descriplion

This work shall consist of the careful and thorough cleaning of the surface of
a preparcd and accepted bituminous or bitumen primed pavemenl course, and
the furnishing and placing on the cleaned surhce of one or two applications
of bituminous material and cover aggregate, all in accordance with this
Specilication and the lines, dimensions and cross-sections shown on the
Drawings and/or as required by thc S.O.

When one application of bituminous material and cover aggregate is placed the
term 'single bituminous surface dressing'(SBSD) shall apply, and when two
applications of bituminous material and cover aggrcgate are placed, the term
'double bituminous surface drcssing' (DBSD) shall apply.

4.2.3.2 Matcrials

(a) Bitruttitrous Material

Bituminous binder for bituminous surface dressing shall be penetration graded

bitumen, or cul-back bitumen, or bitumen emulsion as shown on thc Drawings
or otherwise specified.

Pcnctration gradcd bitumen shall be 80-100 grade conforming to M.S. 124.

Cut-back bitumcn shall be grade RC-70 or MC-70 conforming to M.S. 159.

Bitumen cmulsion shall bc rapid setting of grade RS-I, RS-IK RS-2,

RS-2K or RS-3K conforming to M.S. 161. The grade of emulsion selected
shall be anionic or calionic as appropriatc to the type of rock from which the
covcr aggrcgatc is dcrivcd, and shall be approved by the S.O.

(b) Additives tor Bintminous Mateial

An adhesion and anti-stripping agent shall be added to the bituminous marerial

if the S,O. shall so direct or approve. Thc additive shall be of a typ€ approved
by the S.O. and the required quantity of additive shall be thoroughly mixed with

s4- 12
 (JKR/SPJ/1988)

the bituminous material in accordance with the manufacturer's instructions or

as directcd by thc S,O. for such timc as is necessary to produce a homogenous
mbdure.

(c) Agrcples lor Bituminous Surlace Dressing

For single bituminous surface dressing the corer aggrcgate shall be-nominal
20 mm, tn mm, 10 mm or 6 mm size chippings as sho*n on the Drawing
and/or directed by thc S'O'

For double bituminous surface dressing the cover aggregatc for thc first
aoplication of bituminous material and cover aggregatc shall bc nominal20 mm
si:zc chippings, and thc cover aggregate for the second application of bituminous
material-and cover aggregate shall be nominal 10 mm size chippingg.

Cover aggrcgates shall be screened, crushed stole an! sh-all comprisc clean,
arv. harilouch, sound, angular and cubical chipping free from vegctative and
otf,er orsanic;ratter, clay ind other deletcrious subotanceq and containing few,
if any, fllky or elongated particles. Dusty chipping! shall be washed cleaq all
to thl satiifaction oi the S.O, Cowr agregates shall conform to the follon'ing
phpical and mechanical requiremehts :-

i)' usine thc hoe of bituminous material to bc used in the Works, treated
il
witd'addiiii,e so required, the coated area in the coating and
stripping test for bitumen mixtureg AASHTO Tcst
Mcthod T 182, shall not be ^ggregate
less than 95Vo;

ii) the aggregate crushing value when tested in accordancc with M.S. 30
shall be hot more than 3O;

iii) the weighted average loss of weight in the sodium sulphate soundncss
test (5 cyclcs) when tested in accordance with AASHTO Test Method
T 104 shall be not more than l2Vo;
w) the flakiness index when tested in accordance with M.S. 30 shall'be not
morc than 25;

v) thc polished stone valuc when tested in accordance with M.S. 30 shall
be not less than '10;

vi) thc gradation shall conform to the appropriate envelope shown in

Table 4.4.

4.2.3.3 Eouigment

The Contractor shall provide all thc plant and equipment ngcgssqry tor
executing the work in accordance with this Specification, and shall furnish the
S.O. witfi such details of particular items of cquipment, e.g. manufacturer,
modcl t1pe, capacity, weight, etc., as the S.O. shall rcqui?e.

The equipment shall include a Power br@m, a compressed ait blower, a self'
oroocfed ptessure distributor for bituminous material, all neccssary equipment
ior itotini and heating bituminous material, aggeg^tQ spreading equipment,
a suitablJnumbcr of iiptrucks and a self-propellcd pneumatic tyrcd roller.

s+13
 (JKR/SPJ/1e88)

TABLE 4.4 - GRADATION LIMITS FOR

BITUMINOUS SURFACE DRESSING

Vo Passing By Weight

B.S.
Sieve
Sizc Nominal Nominal Nominal Noninal
20 mm 14 mm 10 mm 6mm
Chippings Chippings Chippings Chippings

25.0 mm 100
70.0 mm 85 -lm 100
14.0 mm 0-20 85 -1m 100
10.0 mm o-2! 85 -lm 100
6.3 mm 0-m 85 -lm
4.75 mm 0- 5 0- 5 0- 10 0-25
2.35 mm 0- 2 0- 2 0- 2 0- 10

(a) Power Broom

The power broom shall be as spccitied in Sub-Section 4.2.1.3 (a).

(b) Canrptessed Air Blower

Thc comprcsscd air blower shall be as specified in Sub-Section 4.2.1.3 O).

(c) Prcssure Distibutor lor Bituminous Molerial

The distributor shall be as specilied in Sub-Section 4.2.1.3 (c).

(d) Srorage and Heating Facililies

lor Bitwninous Material
Storage and heating facilities for bituminous material shall be as specified in
Sub-Section 4.2.1.3 (d).

(e) Agtegate Spreading Equipmenl

Aggregatcs shall be placed using mechanical spreaders of a tlpc approrcd by

the S.O. Thc spreaders shall be capable of applying asgregate uniformly orcr
the full width of the area being treated and shall have controls to regulate the
rate of spread as required by this Specification, all to the satisfaction oflhc
s.o.

(f) TiyTruck
The Contractor shall provide a suitable number of tiptrucks of a typc approrred
by the S.O., capable of spreading aggregate in accordance with this
Specification.

s4-14
 (JKR/SPJ/1e88)

(g) Pneumatic TYred Roller

The oneumatic tyrcd roller shall be of recogrised manufcature and shall be

;nr6"J uy tli s.o. lt shall conforrn 'to the requirements describe'l
bereunder.

Thc oneumatic tyred roller shall bc self-propelled and capable of being

i"u"r[a *itnout facklash; it shall be equipped with power steering and dual
controls allowing operation from either tbc left or right side'

The roller shall have ninc wheels equipped with smooth trcaded tyes all of thc
;;;t; aod.o*ttu"tion, and capa[ib of operating at inflation,presuresof
t" bS Nltq.mm. Five wbeeh shall be on the driven axlc and four on the
"o
.ie"ring o,ti:" At equally spaced on both axles and arran,ed so.that thc tyres
on the s:teering axle lrack midway between those on the driven axle wrth a small
trc ioiler shall be equipped with watcr tanks,-sprinkler systems and
"""4"p.
pads oi coconut matting to keep all tyres evenly wetted during operatlon'

The roller shall be equipped with means- of adjusting .ils total Y?ght !I
U"fi".tine so that the
hallestino
ballasting to 2'o
pet wheel can be varied in the rangc 1'0 to.2'0
the load per
;;;;;;. fi tyt'e-rntlatton Pressurc. snau
weigh-t and the tyre.inflation.pressurc.shall
baliasted weight
tonnes. tn operation, the ballasted
t "p.tation,
uai*aiAio meet the requirements of each particular operation. Elch tyrc
,i"U 6i iipii"flated
,i"U-U" i"ot irflated at the ipecilicd pressure such'that the pressure diffcrencc
6;t*;;ilt
f^' in'
t*. tyres shall nbt exc"ei 0.0+ N/sq'mm' Means
the
shall be-provi{ed
place of the works'
works.
for ^[...t
cbecking o,'.1
and erlhrqlino
idjusting irne
tyre nressures
pressures at all
all times at

The Contractor shall provide the S.O. with a calibration chart for the roller
showing the relationship between the quantily .or depth of ballasr and total
weightiand also a chari showing the rllationship between wheel load, tyre
inflation prcssure and contact prcssure'

4.2,3,4 Construction Methods'

(a) General Condilions

Bituminous surface dressing shall only be carried out in dry,- warm rveathcr
*tr"o ttte surfac€ to bc trealrcd is dry.'Work shall be discontinued when rain
appears imminent and during periods of strong wind'

The s.o. may order the discontinuation of work on account of adverse weather,
*."ilrt".fo.y condition of matcriats, equipment or surface to be treatcd, or
such other conditions as he shall consider detrimental to the work'

O) Su(ace Preparation and Cleaning

Prior to constructing a bituminoui surfacs dressing the surface to be trcated

;i;ii t;"" beeo preiared in accordance with the ippropriate- sections.of this
specification. Nonrithstanding any carlier approval of this surface, any damage
d or deterioration of it stritt Ue made good before surface dressing is
commcnced.

Immediately prior to commencing surface dressing the full wicith of the surface
io Ue ti"";"{t., together with an additional 300 mm width on each sidc, shall be-
sweDt usinc i io*t broom followed by a comprcssed air blower and, if
o""i$*. .o"O.d using hand tools to remove all loose particles, dirt, dust and
otber odictioriable maierial, all to the satisfaction of the S'O'

S,l-15
 (JKR/SPJ/1e88)

In doublc bituminous surface dressing construction, the surface of the first

application of bituminous matcrialand couer aggtegaie rhall be similarly madc
good and cleaned, immediatcly prior to co-mincing ihe second appliLtion.

(c) Appliciation o! Biruminous Mareial

The bituminous material for a singte bituminous surface drcssing or for each
agiJication of bituminous material and cover aggregate of a doubli bituminous
surface dressing shall bc spraycd on to the ciianla surface to be trcated bv
mcan-s ofa pressure distributor. Any areas inaccessible to the distributor spray
bar shall bc treated using the distributor's hand spraying system.

The rate or rates of application shall be as directed by the S.O. based on the
results of laboratory tests. and/or test applications bui for penetration graded
bitumen shall risually be in the appropiiite range given inTable 4.5. -

TABLE 45. RATES OF APPLICATION OF

PENETMTION GRADED BITUMEN

Nominal Size Rate of Application. of Penetration

of Aggregate Graded Bitumen

mmm 2.0 - 3.O litre,/sq.m

14 mm 1.5 - 2.2 litre/sq.m

10 mm 1.0 - r.5 litre/sq.m

6mm 0.7 - 1.0 litre/sq.m

The ratcs of application for cut-back bitumens and bitumen emulsions shall be
commensurately higher depending on their residual bitumen conlents.

The temperature of the bituminous material shall be maintained during

spraying operations within thc appropriate range given in Table 4.6.

The bituminous material shall be distributed uniformly over the surface to be

treated without streaking; the quantiries apflied shalt not deviate by more than
lQTo from those prescribed. The rate of iiplication shall bc checkcd for cach
spraying run by mcasuring the volumc of bituminous material in the distributor
before and aftcr spraying and the area treated. Adjustments shall be medc as
ne-@ssary to ensurc that the prescribed rate of application is maintained in
subsqquent runs-, S-prafng shall be discontinued immediatety if any defect
develops in the distributor, and it shalt not be resumed until the fault has been
rectilied to tbe satisfaction of the S.O.

The spraying of bituminous material over any portion of the surfacc to bc

treated shall not be carried out more than two minutes in advance of placing
the cover.aggregatc on that portion at the specitied rate; and the progiex of"
spraying the bituminous material shall be resiricted as necessary to ioni'ply with
this requirement.

s+16
 (JKR/SPr/1e88)

TABLE 4.6. SPMYING TEMPEMTUNE TOR

BITUMINOUS MATER,IAL

Bituminous Material Spraying Temperatutc

80-100 penetration $o oc to 165 oc

grade bitumen

Cut-back bitumen grade | 50

oc to 65
oc
RC-70 or MC-70

?5oc to 45 oc
Bitumen emulsions

Bituminous malerials shall not be heated to sprafng temperatures too sootr

in advance of requirements. Any bituminous material. which has becn hcated
to spraying lcmperature for morC than ten hours or which has bccn onerhcated
shall bc rejected.

In cases where the bituminous material is applied in lancs therc shall bc a snall
overlap of bituminous material at thc joints behrrben lanes cqual 1n-.wtdth t9
thc edle strip of the sprayed area which docs not rcceive the full rato of
aoolica'iion of bituminous material' For double bituminous surfacc drassing
idi'nrs in thc second application of bituminous matcrial shall bc olfset from
ih*e in the first qplication by 150 - 300 mm for longitudinal joints and by at
least 1.0 melre, whcre possible, for transverse joints.

Each spraunc run stralt commence and terminate on lengths of building papcr
olaccdicrbsithe full spraying width immediately before and after thc scction
io bc sprayed. Sullicient buililing paper shall bc placed so that the distdbutor
."y bi stirted and stopped witlr-thb spray bar o1€r Paper' and so that the
correcr distributor road- ipecd and rate of sPraying can bc maintaincd otr
the cntire length of the section to be sprayed, all to the satisfacbn of thc S.O.
lmmcdiately ifter use and before application of corcr aggegatc' the building
paper shall-be removed and disposed of in a manner approved by thc S'O.

Provision shall be made for a volume of bituminous material of at lcast 1096

of thc capacity of the distributor, or such other guantily ls the S.O. sha[ dircct'
to remai'n in ihc distributor tank at thc completion of cach spraying rutr" in
ordcr to avoid air €ntrapment within the bitumcn sPraying s),stcm'

The surfaces of structures, road furniturc and trees adjaccnt to thc areas being
sprayed shall be proteded in such a manner as to Prcve-nt thlir bc-rng-.spltereq
or m-arred by bituminous material. Bituminous material shall not be dischargpd
into road drains, gttters, etc.

(d) Applieation of Covel AgrcW

Bcforc eacb spraying ruo of bituminous material commences' sullicicnt
aggregate to prbvide lull cover at the prescribed rate of application orrcr thc
eiliriatea to be sprayed shall have been loaded in trucks at the Sitc of the
Works in readiness for spreading

s+17
 (JKR/SPJ/1e88)

Immediately following the application of thc bituminous materiat, the clean,

dry cover aggrcgate shall be uniformly spread over the bituminous material
using ,mechanical spreaders approvod by the S.O. Thc aggrcgate shall bc
placed as quickly as practicablc after the application of bituminous matcrial on
all parts of thc area to be covered, and for tro portion' of the surfacc to bc
treated shall thcre bc a delay of more than two minutes between tbc
application of the bituminous material and the spreading of tbc aggregate,

The trucks ftreding the aggregate to thc mechanical spreaders shall operate
backward durirrg aggregate spreading in order that thc whecls of tbe spriaders
and trucks shall not run on uncovered bituminous matcrial,

The rate of application of cover aggregate shall bc as directed by the S.O.

based on the results of laboratory tests and/or tests applicatiorc, but shall
usually be in the appropriate range given in Table 4.7.

TAITLE 4.7 . RATES OT APPLICATION OF

COVER AGGREGATE

Nominal Size Rate of Application

of Aggregate

Z) mm r7 - n kglsq.m

14 mm 12 - 18 kglsq.m

l0 mm 8 - 72 kglsq.m

6mm 5 - 8 kglsq.m

The rate of application shall be checked for each spraying run from
measurements ofthe quantities of aggregate in the trucks and thc area treatcd,
or by sampling and measuring the aggrcgate spread on the road. Any barc or
insufliciently covered areas shall be made good by hand spreading as quickty
as possible. Aggregate in excess of the rare prescribed shali bc Lvenly
distributed over the surface or removed as quiclly as possible, all to thc
satisfaction of the S.O.

In cases where thc surface dressing is constructed in laneg the edge of the
aggregate spread adjacent ro an untreated lane shall coincide with thc edge of
the sprayed area which receives the full rate of application of the bituminous
material. This will leave a narrow strip of bituminous materid of partial
thickness wbich shall be overlapped by the bituminous material spriy and
aggregate spread of the adjacent lane.

Immediately following the spreading of thc aggregaae to the satisfaction of the

S.O., the aggregate shall be rolled with a pneumatic tyred roller approved by
the S.O. to embed the aggregate in the bituminous material. Rolling shail
commence as quickly as practicable after the application of the bituminous
6alerial and aggrcgate on all parts of the area to be coverd and for no
portion of the surface to be treated shall there be a delay of more thaa 3

S,l-18
 (JKR/SPJ/1e88)

minutes bctween thc application of the bituminous material and the

commenccmeot of rolling.

The pneumatic tycd rolter shall be ballasted to an operating weight of 9' l0

tonnes and its tyre inflation pressure shall be 0,53 N/sq.mm for surfacc dressing
work. Rolling shall be continucd for as long as is necessary to thoroughly
cmbed the agg'.egate in the bituminous material, all to the satisfaction of lhe
s.o.
Rolling shall generally bcgin at the outer cdge of surface dressing and Progress
'uniformly towards the centre on. each side, except on superelevated cunes
where rolling shaU begin at the lower edge and progress uniformly towards the
higher edge. Consecutivc roller passes shall generally overlap by about one half
of thc roller's width.

When, in the opinion of the S.O., the bltuminous material has hardened
sufficiently to prevent thc dislodgcment of embedded aSgrcgate by the action
ofthp power broom, all loose aggregatc shall be swept from the treated surface
using the powcr broom and compresscd air blowcr and disposed of to the
satisfaction of the S.O. Whcre tbe dressing so prepared is the {irst applitation
of a doublc bituminous surface dressing construction of thc second application
bf bituminous material and cover aggregate shall then proceed as soon as is
practicable.

(c) Openittg to Trolfic

Bituminous sqrface dressing shall normally not bc opened to traflic until

such time as, in thc opinion of the S.O., the surfacing shall havc developed
sufficient stre ngth to withstand normal trallic forccs without dislodgement
of the aggregite. This will usually be not less than 24 hours after the
completion of rolling Where it is necessary to allow earlier use of the
finishcd surface to facilitate the movement of traffig vehicles may be allowed
to run on the wgrk after rolling has been completed, provided that spccds
are restrictcd lo 30 km per hour or less and sharp turning movcmcnts ate
prohibiied. The linished surface shall sub,scquently have to be closed
iemporarily lo enable thc loose aggregate to be swept off and disposed of as
described in Sub-Section 4.2.3,4 (d).

Ideally, the first application of bituminous material and cover aggregate oI a

double bituminous surface dressing should not be opened to traffic before
construclion of the second application. However, where it is necessary to
facilitate the movement of traffic, the lirst application may be opened to traffic
prior to construction of the second application. Nevertheless, traflic movement
on the completcd firsl application shall be kept to a practicable minimum and
the second application shall be constructed as soon as is practicable after the
completion of the fir.st.

s4- l9
 (JKR/SPJ/1e88)

4.2.4 Asphaltic Concrete

4.2.4.1 Descriltion

This work shall consisr of furnishing ptacing shaping and compacting asphaltic
concrete binder course and/or wearing course otr a prepared and acccpted
bituminous oq bitumen primed pavement course, and shall include thc careful
and thorough cleaning df surfaces which are to be covered without receiving
a bituminous tack coat. Tbe work shall be carried out all in accordance with
this SpccificatiOn and tbe lines, levels, grades, dimensions and cross-sections
shown on the Drawings and/or as required by the S.O.

4.2.4.2 Materials

(a) Aggregates

Aggregat€ for asphaltic concrelc shall be a mixture of coarse and fine

filler, The individual aggrcgrtes shall be
aggregatcs and, if necessary, mineral
of sizes suitable for blending lo produce the reguired gradation of the
combined agfrregate, all to thJsatisfaction of the S.O.

Coarse aggregates shall be screened crushed hard rock, angular in shape and
free from dust, clay, vegetative and other organic matter, and other deleterious
substances. They shall conform to the following physical and mechanical
quality requirements :.

i) the aggrcg ae crushing value when testcd in accordance with M.S.30

shall bc not more than 3O;

ii) theweighted average loss ofweight in the sodium sulphate soundness

test (5 cycles) when tested in accordance with AASHTO Test Mcthod
T 1O{ sball be not more than l2Vo;
iii) the flakiness index when tested in accordancc with M.S. 3O shall be not
more than 30;

i") the water absorption when tested in accordance with M.S. 30 shall be
not more than zVo;

v) the polished stone value when tested in accordance with M.S. 30 shall
be not less than,$ (only applicable to aggregates for wearing course).

Fine aggregates shall be clean natural sandg screened quarry fines, or mining
sand. Mining sand shall be thoroughly washed before usc. Other typcs of fine
may bc used subjecr to the approval of the S.O. Fine aggregates
be non-plastic and 'free from clay, loam, aggregations of material,
^ggr]egate
shall
vegetative and other organic mattcr, and other dcleterious substanccs. They
shall mnform to the following physical and mechanical quality
requircments i
i) the wcighted average loss ofweight in the sodium sulphate soundness
tcst (5 cycles) when tested in accordance with AASHTO Test Method
T 104 shall be not more thanl2Vo)

iD the water absorption when tested in accordance with M.S. 30 shall be

not more lhaa ZVo,

s+20
 (JKn/SPJ/re68)

Notwithstanding compliance with the rcquirements of this Spccilication'

limestone aggregates shall not be permittcd for use in wearing coursc.

Thc gradation of thc combined coarsc and finc aggregate$ _togcthcr with
ordinary Portland cement added as an adhcsion and anti-stripping apnt and'
il necessary, any other minerd filler, shall conform to thc apProPridc cnrelopc
shprm in Table 4.8.

TABLE,|a - GMDATION LIMTTS FOn ASPHALTIC

CONCNETE

Mix Typc Wearing Bindcr Bindcr

Coursc Coursc Courec

Mh Designation ACW14 ACB14 ACB28

B.S. Sieve Sizc % Passing By Wcight

n.5 mm 1m
8.0 tnm 80 -r(n
N.0 mm 72 -v3
14.0 mm 80.95 n -95 58 -82
10.0 mm 68 -90 56 -81 50 -75
5.0 qm 52 -72 40 -65 5 -58
335 mm 45 -62 32 -58 n -52
1.18 mm 30.45 m -a 18 -3E
425 um 17 -30 t2 -A ll -E
150 um '47 -10
-16 6 -16 5 -14
15 um 4 - E 3 -8

Thc gradation cnvclopes in the abovc Table arc purposcly widcr lhaa tbc
tolcrances for good worl! control of asphaltic concretc qixcs -f- -$ typ
of mix required in tbe Worts, thc Contraclor shall establish a job mix fornula
gradation-which shall consist of a singlc dcfnitc p€rccntags passing- for cacl!
iieve size in thc above Tablc and shall produce a smooth curw witbil and
cssentially parallel to the appropriatc gradation cnvclopc. fhis job 4ix-fgq{a
gradation, with thc allowable tolerances for a singlc lcsl as spccified in Sub
Section 4.2.4.3 (c), then bccomcs thciob control envelopc and tbis job control
envelope must bc totally within thelimits of the appropriatc gradation enrelopc
in thc above Table.

(b) Minenl Filler

Mincral filler shall bc fincly divided mineral matter such as roc& drst, lincstonc
dust, hydrated limc, hydraulic cemcnt, or such othcr suitablc malorial as thc
S.O. shaU approvc. Ai therimc of mixing with bitumen it shall bc sulfrcicntly
dry to 0ow fieely and shall bc esscntially frcc frodr agglomcrations Not lcss
thanT0r.9b by wcight shall pass thc 8S.75 um sicrE.

s+21
 (JKR/SPJ/1e88)

(c) Biuminous Mateial

Bituminous binder for asphaltic concrete sball be penetration cradcd bitumen

of 80-100 grade conforming to M.S. 124.

(d) Anti-Stipping Agent

Ordinary Portland cement shall be added to the combin el agregate for

asphaltic concrete to serve as an adhesion and anti-strippiag agent. ffe
-by
amount of cement added for this purpose shall bc ZVa weight of the
combined aggregate, (Additional cement may also bc added, if aecessary, to
serve as filler.)

Ordinary Portland cement for this purpose shall conform to thc requirements
of M.S.522 and shall be dry frec flowing and frec from agglomerations at thc
time of use.

Notwithstanding the use ofordinary Portland cement as an anti-stripping agent

as sJrccificd abovc, the Contractor shall be responsible for ensuring tlraithc
bitumcn bindcr adherds satishctorily ro the aggregate and does not itrip fron
it during thc service life of the asphaltic concrltc.
Accordingly,_ the Contractor shall carry out bitumcn stripping tcsts with
the proposed aggregates to demonstrate to tbe complete satisfairion-of thc S.O.
that the aggregates will perform satisfactorily in servicc with the specificd
bitumen binder. Such tests shall be canicd oul ia accordance with AriSlfTO
Test Method T 182, or such other tesr methods as the S.O. shall direct or
approve. When AASIITO Test Merhod T 182 is used, tbe coated area at the
end of the mixture's period of immersion in water shall bc not less than g5%.

Wherc, in tbe opinion of the SO., ordinary Portland cement does not pcrform
satisfactorily as an anti-stripping agent, ihe Contractor may proposc to usc
another adhesion and anti-stripping agent in addition to, or wh;llyor partialty
instead of, thc ordinary Portland ccment specified above. Such alcnitall Ui
9l a lype approved by the S.O. and shall be thoroughly mifta witU ttc
bituminous binder, all in accordancc with the manufactuier;s instructions, ln
such a case, the agent shall be addcd to the bitumen binder used in thc
bitumen stripping tests in the appropriate amount and manner.

Aggregate which does lot perfolm satisfactorily in the bitumen sripping tcsts,
using the approvcd- adhesion and anti-stripping agent when appropriate, shali
not be uscd in asphaltic concrgte.

4.2.4.3 Asphaltic Concrete Mix Design

(a) Job Mix Fonnuloe

After obtaining supplies or production (as applicable) of all aggregates

consisrcnt as to gradation and other qualities, thi Contractor shalt piofsc a
job mix formula for each class of mix required in the Works. In ordei toattain
optimum guality of the mixtures, the job mix formula for each class shall be
preparcd on thc basis of tcsting sevcral trial gradations within the limits set in
Table 4.8 at an range of bitumin contents. As a guidc to rhe
-appropriate
tcsting range of bitumen coRtents, the design bitumen content wiJl usualty bc
in the appropriate range given in Tablc 4,9-.

s4-22
 (JKR/SPJ/1e88)

TABLE 4.9 . DESIGN BITUMEN CONTENN

ACW14 - Wearing Courso 5.0 - 7.0 %

Agw14 - Binder Course 4.5 - 6.5 %

AcB 28 - Binder Course 4.0 - 6.0%

A samole each trial mir (i.c' each combinatioo of trid Sradation and
of
bitumcl content) shall be subject to a comprchcnsive Marshdl mcthod test and
analysis as follows :'

i)' oreoaration of specimens for the standard stability and flow test io
lccirdance with AASHTO Test Method T 245 using the 75 blows/facc
comPaction standard;

ii)' determination of the bulk specific gravity of the specimcns in

accordance with AASIITO Test Method T 166;

iii) determination of the stability and flow vaiues in accordancc with

AASHTO Test Method T 245;

iv)
' analrrsis of the density and voids parametcrs to dcleiminc the
percentage of voids in ihe compacled rygegatc, the percentagc of
i,oids in iie compacted agtegaie filted with bitumen, and hencc the
percentage of air voids in the. compacted rnix

For trial mix conlorming to a propoced job mix formul4- thc paramctcrs
eac.h
.iil" "Uoo tests and.anafses sfrafconform to thc requiremcnts of thc
approt'riatc type of mix as given in Table 4.10.

TABLE 4.TO . TEST AI\TD ANALYSIS PARAMETENS

FOR ASPHALTIC CONCRETE

Parameter Wearing Course Binder Coursc

Stability S >500kg > 450 kg

Flow F > 2.0 mm > 2,0 mm

Stiffness S/F > Zfi kg/mm > 275 kg/mm

Air voids in mix 3.0Vo ' 5.OVo 3r% - 7.0%

Voids in aglegate
filled with bitumen 75% - 85% 65Vo ' 8O%

s+23
 (JKR/SPJ/1e88)

Air voids shall be dcfined as the small pockcts of air bctwpea thc coated
aggrcgatc purticlcs in a compacted asphdtic concrete mix. The portion of the
bitumen absorbcd into the agregate particles must therefore bc allocrcd for
when calculating the air voids. For combined aggregate with a watcr
absorption of not more thall.l.O%, the absorbed bitumen may bo cstirratcd on
thc.basis that the absorption of bitumcn will bc approximately 2096 of thc waic
absorption.

Voids inrhc aggregate ofa mix shall bc calculatcd on the basis oftbe wcighted
averagc bulk ipccific gravity on an ovcn dricd basis of thc coarsc and frnc
aggregatc fractions (separated by the ASTM # 10 sieve or B.S. 10 mm sievc)
as determined in accordance witb AASHTO Test Method T 84 and T 85 as
applicable.

Tbe Marsha{l dcnsity of an asphaltic ooncrete mix is defined as the avcragc

dcnsity of a sct of three (3) test spccimens moulded for the standard stability
and flow test in accordancc wirh AASHTO Test Method T 245 using thc 23
bloua per facc compaction standard.

The Contractor shall submit to'the S.O. full details of his proposcd job mix
formula for each class of mix required in the Works including :-

i) the gradation analysis of each aggregate lo bc used in thc mi:q

ii) the proportions for cold batching the aggregates;

iii) the mixing plant screen sizes, tbe smallest of which shall generally bc
not mofe than 3.2 mm;

w) the gradation anatysis ol the aggregatc in cach of thc mixing plants'

hot bins and of ths mineral lillcr (including any ordinari Porttand
ccment added as anti-stripping agent);

v) thc job mix formula gradation of the combine d agregateand filler;

vi) thc proportions for combining thc hot bin aggregates and liller;

vii) thc bitumen content (by weight of total mix);

thc dry and wet mixing times if a batch plant is to be used, or the
"iiD mixing time if a continuous mix plant is to be used;

ix) thc full results of the comprehensivc Marshall method tests and
analyses as dcscribed above for each trial mixused in determining the
job mix formula.

Thc S.O. may rcquire changcs of any of the factors in each proposed job mix
formula and further tests and, analyses in order to attain optimum qriality of
thc asphaltic concrete mixcs.

(b) Plant Tiols

After having rcccived thc S.O.'s prcliminary approval of his proposed job mix
formulae, the Contractor shall arrangc to milq lay and compacf alphahic
concrclc- conforming to thc proposcd formula for each class of mix required
in thc Works. A minimum of l0 ronncs of each mix shall be placcd ii trial
arsas to dcmonstrate to the satisfaction of the S.O. that the mixing laying and

s4-24
 (JxR/sPJ/1e88)

compacting cquipment conforms to thc reqlircmcnts of this $cciftcatiott'

and ihat th-e prbpbscd mixes are Thc trial areas shall not.bc part
of thc Contraa'Worls but shall bc proided by the Coatractor at bis wl
Gxpense. Thcy shall bc approved by the S.O.

As dir€dcd by thc S.O, comprcbensivc qnPf.nS and tcsting $

"lf:t.Up nix
mix shall be ;anied out to ch-ccl for satisfacory complianoe with is i<$
formul4 and for a satbfactory dcgrcc of compaction.

As a rcsult of thc plant ttiab tbc S.O. nay reguirc am91{ncnp !o tbcio!
mix fornulac, frrtlcr tcss and analysc.s, and pcsibly additional- plant- trialr
bcforc finally approiag the mixcs f6r fult scalc producrion and uec in thc
Worts.

(c) Compliancc with the lob Mix Fonnulac

The S.O.'s final approval of thc job mix formulae shall bind thc' Contractor
to furnisb asphattii cotrcetc m-ixar mccting rhc prccisc gradations - and
bitumen contents spccificd in thesc forrnulac within the tolcranccs rct forth
in Tablc 4.11. '

Moditications to a job nh formula may onlybc madc with thc approal of thc
S.O. Shoutd thc Sb. at any time haw icason to belicnc that thc ndcrials end
methods of mixing and laying arc diffcrcnt fron thqc approrrcd' hc thall so
advisc the Contractor, and may ordcr that asphaltic ooncrctc worls bc
discontinued pending further trids and tcsting'

TABLE 4.ll : TOLERANCES FOR ASPHALITIC coNcnETE MIXES

Parameter Pcrmissiblc Variation

'%Bywei$t of Total Mix

Bitumen. + 02Vo

Fractions of combincd
agg'cgate passing 5.0 mm
and larger sicvcs. ! 5.0%

Fraclious of combincd
aggl.egate passing 3.35 mm
and 1.18 mm sicws. + 4.0%

Fractions of cclmbincd
aggregatc passing 425 um
and 150 um sicves. t3n%
Fraction of cornbined
aggregale passing 75 um
t 2.0%

s&25
 (JKR/SPJ/1e88)

4.2.4.4 Eouioment

Thc Contractor shall provide all the plant and equipment necessary for
executing the work in accordance with this Spccification and shall furnisb the
S.O. with such details of particular items of equipment, e.g. manufacturer,
modcl typc, capacitn weight, opcrating featureE etc., as the S.O. shall require.

(a) Road Cleaning Eqtipment

Road clcaning equipment will be required where asphaltic concrete is to be laid

on a surfacc which is not to receive a tack coat. The equipment shall bc the
same as that required for preparing a surface for a
tack coat, and shall
include a powcr broom and compressed air blower as specified in Sub-Seaions
4.2.I.3 (a) and 4.2.1.3 (b) respectively.

(b) Asphalt Miring Plant

The asphalt plant shall be either a batch plant or a drum mix plant or a
continuous mix plant of recognized manufacture and shall be approved by the
S.O. It shall conform to the requirementS described hereunder.

The mixing plant shall have a capacity suited to the Works and sufficient to
enable the paver to operate more or less continuously when paving at normal
speeds at the reguired thicknesses. The plant shall be so desigred as to enable
consistent production of asphaltic concrete mixes within the tolerances
prescribed in this Specilication, all to the satisfaction of thc S.O.
Scales for alt weigh boxes or hoppers shall bc of the springlcss dial t1pe,
accurate to withi4 0.5% of the maximum load that may be required. Scale dials
and pointers shall be easily read from their bperator's normal position without
significant parallax errors. Scales shall be subitantially constru-ted so that they
shall maintain their accuracy after initial adjustment. The Contractor shall
furnish not less than ten 25 kg test weights.at the plant for checking adjusting
and calibrating scales.

Tanks for storage of bitumen shall have a capacity suited ro the proposed rate
of utilization of the material and the method and frequency of its dclivery to
the Works, all to the satisfaction of the S.O. The tanks shall be provided with
m_eans of measuring the volume of their contents at all iimes and of drawing
off samples of the contents. The bitumen feediirg system shall providc foi
continuous circulation of hot binder through thc system and back into the feed
tank, The end of the return line discharging into the feed tank shall always be
kept submergcd in the bitumen in the tank in order to prevent oxidation ofthe
returning hot bindcr. The storage tanks, and where necessary barrel decanters,
and all elcmcnts of the bitumen fecding system shall be equipped with hcating
systems or insulating jackets as necessary to provide for effective and positive
control of the tempcrature of the bitumen at all timcs up to the temperature
required for utilisation. The method of heating shall be such that neither
flames nor the products of combustion shall come into direct contact with the
bitumen or the casing of its immediate container, and such that no portion of
the bitumcn shall be subject to overheating,

Thc plant shall be provided with accurate mcch.rnical means for uniformly
feeding the aggregates into the dryer so that uniform production and
temperature of the heatcd aggrigates will be obtained. A sCparatc fccd bin
with an.adjustablc gate opening shall be provided for each jggregate to be
included in the combined aggregate for the mi4 normally four bins will be

s4-'26
 (JKR/SPJ/1988)

rcouired. The feed bins and gatcs shall be so constructcd and equipped that
they shall bc readily acccssible for calibrating at all timcs, and shall Provide for
a 6ntinuous and uniform tlow of each ag1eg^te required in thc mir

The plant shall havc a rotary drum drler of satisfactory design for drying and
bcatib the combined aggrri!3te so that its temPeratute will bc at thc rcquircd
lerrel aithe time it is mixcdfrth the bitumen. Thc burner shall bc so designed
that complete combustion of the fuel will be obtaincd, and the aggrcgatc will
remain clean and not become coated with soot or oil.

The plant shall be cquipped with four (or morQ scrcensr the smallcst of which
shall rcncralty bc uot- more than 3.2 mm. The sccens shall harc a normd
capaity sligbily in excess of the maximurn output of the mixing plant. Thc
scrccni shall be readily acccssiblc for inspedion.

The plant shall include four (or morc) storage bins for screened aggrcgatcq
each with a capaoty of not less than twice tbc pugnill dead load cap-aoty. TE
bins shall be a'tranled so as to providc scparate ilry storage for each scrccncd
fraction of the aggregatc.. Each bin shall be provided wlth an gvP:flolfl Pipc
of such sizc and lotation as to prevcnt any backing up of matcrial into olhcr
bins. Eaeb bin shall be so con{tructed that represntative 8ggregatc samplcs
can bc readily obtaincd, and shall have means for obscrving rhc-aggr. cgatc lcvcl'
Scparatc dry storage shall be providcd for mineral fillcr, and the plant shall bc
sat-isfactorily cquippcd to feed filler into the mircr.

Satisfaclory means by either weighing or mbtcring shall bc progdci to obtain

thc ore.scr,ibed amount of bitumcn in the mix within the specified tolerancc.
Mcias sball be provided for checking tbe quantity or flov ratc of binder
cntcrinr tbe mixer. Suilable rneans ihdl be provided for maintaining thc
pt"scti&d tempctature of thc bitumen in thc pipelincg weigh buckct or llor
Dgter, rrrd spray bars.
oC to 2m oC shall bc frtted
An armoured thermorneter with a range of 30
in thc bitumen fecd line at a suitable location near thc discharge vahc at thc
mixcr unit. Suitablc did<calc mercury actuatcd thermometcq clcdric
DlToncters or othcr thermomctric instruments shall be litted at the dischargc
cf,ute of thc dryer and in each hot aggregete storage bin to indicatc thc
tcmperaturcs of thc heatcd aggregatcs.

The plant sball be equippcd with a drst collector so constructcd 8s to wastc

the natcrid collected or feed it uniformly to the heated aggregate.

Thc ptalt shalt be cquipped with ade4uate and safe stairways to thc mixing
phtf6rm
-oro,idc and sanpliirg'iocations, andguardcd laddcrs and cat'walks shall
aooqslr to all- olhcr positions as necessary for proper opcration'
inspcaion and maintenancc oitbc plant, all to thc satisfaction of thc S.O. All
gcirs, pulc),s, chains" sprockets and other dangcrow moving parts t-tt".|l F
itopcrly guarded and protected.
-ptatform, Ample and unobslructed spacc shall bc
itoi,iaei 6n the mixing and cliar and unob,structed Passagc shall bc
haintained at all timelin and around the truck loading arca, which shall bc
tept frec from drippings from the mixcr.

SDccial Rcquirements for Balch Plants

Eac.h storage bin for scrccned aggregate shall bc provided with a bottom outlet
getc so corltrucled as to prcvcnileatage whcn closed. Thcsc gates shall harc
a quid and complctc closing action.

s+27
 $;** (JKR/SPJ/l!AE)

The planr shall bc equipped with a weigb box or hoppe.r for accurately wcighing
out aggregate from each of the screencd aggregate storage bins. The weigh
box or hopper shall bc suspended from its scale's lever mechanism and
shall bc sufficiently |arge to hold a full batcb equal to rhe pugmill capacity
without hand rating or spilling of the aggregate. The dischargc gate shall be
so constructed as to allow rapid and complete emptying of the weigh box or
hoppcr into lhe mixer, and preyent leakage when closed.

The plant shalt be equippcd with a binder wcigh bucket which shall bc charged
through afast dcting non-drip valve in the binder feed pipe located directly oreer
thc bucket. The bucka shall bc suspcnded from its scale's lever niechanism
and shall have a capacity sufficicnt to weigh out binder up to Z) Vo oI the weig$t
of the pugmill dcad load capacity. Tbe bucket shall harre a dischargc
mechanism irhich shall providc for rapid and complete ernptyrng of the bucket
in a thin uniforrn sheet or multiple sprays over the full len6h and riridth of thc
mircr. The discharge mecbanism shall not leak or drip when closed.
The batch mixcr shall be a suitable twin-shaft pugmill, with a capacity of at
least 500 kg of asphaltic cotrcrcte, capable of producing a thoroughly
honogeneous mixturb, The clearance of the paddlE blades from all fixed and
moving parts of the mixer shall be not more than Z) mm. If the pugnrill is not
enclosed it shall bc eguipped with a dusr hood to prcvent loss of lines from the
minure. The discharge gate shall be so constructcd as to allow rapid and
complete emptying of thc mixer, and prevent leakage of any mix constituent
when closed.

Thc mixer shall be equipped with an accurate tirne lock system for controlting
the operations of a complete mixing cyclc. It shall lock the aggregate weigh
box or hoppcr gate after charying the mixer with aggregate, until the ctosing
of the mixer gate at the completion of the mixing cycle; it shdl lock the binder
weigh bucket discharge mechanism during the dry mixing and wet rnixing
periods. (The dry mixing period is defined as the interval of time bctu'ecn the
opening of the aggregate weigh box or hoglpl gatc aodlhe start of discharging
tlftfnler"fli0@-bucket. The*et mixing period is defined as thc interval ol
time bctwpen the start of discharging the binder weigh bucket and the opening
of the mixer gate.) Thc dry and wct mixing periods shall both be adjustabli
in incrcmcnts of not more than 5 seconds from zero to not lcss than 1Z)
seconds total for dry and wet mixing,

Special Requirements for Drum Mix Plants

Tbe cold material feeder unil shall consist of not less than 5 compartments with
suitable heaped capacity appropriatc for the plant. Each bin shitt Ue provided
with a control gate and measuring feeder suitable for accurate blending of the
aggregates on to the cold fecd collecling conveyor. The cold feed system shall
incorporate,a device for moisture compensation capable of producing an
accuiatc and continuous blend of the individual agregaae sizes irom the cold
fced compartment.

The drum mixcr shall be ofan inclined, oiFfired and parallel flow type in which
the aggregates and exhausl gases flow in the samc direction. Thc drum mixer
length to diameter ratio shalt be such as to ensurc efficicnt drying and intimatc
qrl1rg qt aggrcgalc, fillir and binder ovcr thc full rangc oi rated opcraring
-of
efficiencies. A bypass chute shall be incorp,oratcd ior sampling cold
aggregate.

S,l-28
 (JKR/SPJ/1988)

Freshly mixed material shall be delivered and stored in a surge silo through
a proper conveyor system.

Special Requirements for Continuous Mix Plants

Each storage bin for screened aggregate shall be provided with an accurately
controlled variable orifice gate discharging on to an aggregate feed mechanism'
The dischargc orifice shall be rcctangular with one dimension variable by
means of an adustable and tockable gate, which shall have an indicator showing
the distance it is open. These gates shall be used for accurately proportioning
the screened aggregates for the mix'

The plant shall have means of calibrating the aggregate bin discharge gate
openings by weighing test samplea obtained by diverting the aggregate fed-out
ol each bin into a suitable test box. Test boxes shall have a capacity of not less
than 100 kg each.

The plant shall have satisfactory means ofeffecting positive interlocking control
between the flow of screened aggregates from thc storage bins and the flow
of binder from the meter or other'proportioning device. This control shall be
accomplished by interlocking mechanical means or another positive method
satisfactory to the S.O.

The continuous mixer shall be a suitable twin-shaft pugmill with an adjustable

dam and paddles with reversible blade pitch for adjusting the volume of mixture
held in the pugmill. The clearance bf thc paddle blades from all fixed parts
of the mixcr shall be not more than 20 mm. The bindcr shall b€ fed into the
mixer through a spray bar directed on to thc aggregate across the full width
of rhe pugmill at the feed end. The discharging mixture shall pass over the
darn inio a hopper with a discharge gate so constructed as to allow rapid and
complete emptying of a hopper, and prevent ieakage of the mix when closed.
The mixer shall be equipped with a permanent gauge for measuring the depth
of mixture in the pugmill and a manufacturer's calibration platc showing thc
volume of rnixture in the pugmill at each increment of depth.

The mixing time shall be determined using the formula:-

Mixing time (seconds) = *ad weight of mix in Dugmill !kg)

Pugmill output (kg Per second)

and for a given output it may be varied slightly by adusting the depth (and
hence weight; of the mixturc held in the pugmill by varying the dam height'
the configuration of the paddle blades, or both. However for substantial
adjustmenis of the mixing time, in order to maintain thc depth at a level
compatible with efficient mixing, i.e. so that the paddle tips just breat out of
the mixture at the height of their action, the iate of feed of materials to the
mixer (and hencc output) should be changed.

(c) Tip-Trucks

The Contractor shall provide a suitable number of tip-trucks of a type approved

by thc S.O. for transporting asphaltic conqete from thc mixing plant to the
piving works. The trucks shall have trays with smooth, flat beds and sides, and
shall ha"e load capacities of not less than 5 tonnes. hior to loading, thc inside
of each uuck tray shall be lightly and evenly coated with a soap or detergent
solution, or such other liquid as the S.O. shall approve, to prevent adhesion of
the asphaltic concrete. The trucks shali bc equipped with covers of canvas or

s4-29
 (JKR/SPJ/r988)

other suitable material to protect the asphaltic concrete.

(d) Asphalt Paver

The asphalt paver shall be of recognized manufacture and shall be approved

by the S.O. It shall conform to the requirements described hereunder.

The paver shall be self-propelled and capable of reverse as well as forward

travel. It shall be equipped witb a hopper at the front designed to receive the
paving mixture from tip-trucks, and shall have a mechanical distribution system
for spreading the mixture evenly and without segregation over the surface to
be paved in front of a screeding and compacting unit which shall be equipped
with a suitable heating device. The screeding and compacting mechanism shall
be capable of confining the edges of the material being laid without the use of
stationary side forms, shall be adjustable to strike off thc mixture to the
thickness and cross-section shape required, and shall be controlled by an
automatic levelling device to produce an even carpet of bituminous mixture
with a uniform surface texture free from indentations, ridges, tear marks or
other irregularities. The paver shall be capable of laying the bituminous
mixture in paving widths in the range 2.5 to 3.75 m and of finishing the
pavement layer true to the required lines, grades, levels, dimensions and cross-
sections, subject to compaction by rolling, all to the satisfaction of the S.O.

(e) Rollers

A pneumatic tyred roller and two steel wheeled tandem rollers shall be
provided. However, a three wheeled steel roller may be substituted for one of
the tandem rollers if
the S.O. shall so approve. All rollers shall be of
recognized manufacture and shall be approved by the S.O.

The pneumatic tyred roller shall be as specified in Sub-Section 4.2.3.3 (g).

Steel wheeled rollers shall conform to the requirements described hereunder.

Steel wheeled rollers shall be self-propelled and capable of being reversed

without backlash; they shall be equipped with power steering and dual controls
allowing operation from either the left or right side. They shall be equipped
with water tanks, sprinkler systems and scraper blades to keep all wheels evenly
wetted and clean during operation.

Each steel wheeled roller shall be ballasted so that its total operating weight
is in thc range 8 to l0 tonnes and its driven roll (or rolls) shall exert a rolling
force of not less than 3.5 tonnes/metre of roll width. The Contractor shall
provide the S.O. with a calibration chart for each roller showing the
relationships between the quantity or depth of ballast and total weight and
rolling force.

4.2.4.5 Construction Methods

(a) General Conditions

Asphaltic concrete paving work shall only be carried out in dry weather when
the surface to be covered is dry, or if so specified, has received a bituminous
tack coat which shall have achieved a satisfactory degree of tackiness, all to
the satisfaction of the S.O. All laying, rolling and finishing work shall be carried
out during daylight hours, unless the Contractor shall have provided suitable
flood-lighting for the job site, to the satisfaction of the S.O.

s4-30
 (JKR/SPI/1e88)

The S.O. may order the discontinuation of wcrk on account of adverse weather,
unsatisfactory condition of materials, equipment or surface to be paved or such
otber conditions as he shall consider dctrimental to the work.

(b) Swface Preparation and Cleaning

Prior to constructing an asphaltic concrete pavcm€nt layer, thc syfacc to bc

covered shall have Een prepared in accordance with the appropriate -Scdions
of this Spccification. Noiwiihstanding any earlier approval of thissurfacc, any
damage io or deterioration of it shall bc made good before asphaltic concrctc
paving work is commenced.

Ifthe surfape to be covered is not to be provided with a bituminous tack coat,

tben immedhtely prior to commencing asphaltic concrete Pa!ry' it shall bc-
swept using a po*et broom fotlowed by a compressed air bloler and' if
neccssary scrafea using hand tools to remove all loose- particles, dirt' dust
and other objeitionable nraterial, all to the satisfaction of the S'O.

If the surface to be covered is to be provide! with a bituminous tack coat, then

. this shall be applied alt in accordance with the provisions of Sub'Section 4.2'2

(c) Agregote Handling and Heating

Each aggregate to bi used in thc asphaltic concr€te mixes shall bc stored in

a scparle itockpilc near the mixing plant. Stockpiles of sand and other fine
aggregates shalf bc kept dry using waterproof covers and other mcans as
n6fussaty. ln placing tle aggregates in the stocl:piles and loading them into
the nixiirg planfs cold agglegate feed bins, care shall be laken to prevent
segregatiin br uncontrollA combination of materiats of diflercnt gradation'
Selgrelatea or contaminated materials shall bc rescreened or rejected for use
in thc Works and removed from thc mixing plant site.

The aggregates shall be fed into the dryer at a uniform rate p^roportioned in
accordind with thc appropriate job mix formula. The rate of feed for cach
agg:egate shall be mainiained within l0% of the rate prescribcd, and the
tid iatc of feed shal! be such that the plant's screens shall ncver bc
overloaded.

Thc aggregates shall be dried and heated so that when delivered to thc mixer
oC to 170 oC.
thcy sf,-al'bc at a tcmpcrature in the rangc 150

Immediately after heating the aggregates shall be screened into four (or-more)
fractions w[ich shall be Jeparatiiy siored in the hot aggregatc storage bins in
rcadiness for mixing,

Ordinary Portland cement and/or other mineral filler to be used in.the mix
shall bc-stored separatety and kept completely dry' Its rate of feed into the
plant shall be accurately'controlled by weight or volumctric measurement, all
to the satisfaction of the S.O,

(d) Heating of Bitumen

The binder shall be heated so that when delivered to the mixer il shall be at
oC.
a temperature in the range 140 "C to 160

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 (Jr(R/SPJ/1e88)

(c) Miing Aspholtic Concretc

Thc- mixing plant shall bc so.coordinated and opcrated as to consistcatly

prodyge asphaltic concrete mixes within the totirances prcscribed in thii
Snecification, all to the satisfaction of thc S.O,

Mirinq in Bdtch Plants

For each batch thc screcocd hot aggrcgates shall be wcighcd out into tbc
agregatc rvciqf, h9pq9r in accordancc with thc proportions prascribcd in tbc
appro-priate job mix formula; tbe scquencc of weighing out-shdl oommcncc
with the largest sized aggregatc and piogrcss down to thE frncs, unhss thc S.O.
shall- othcnrisc approve. Mineral frller shall bc weighed out itrto thc fillcr
wcigh hoppqr, whcre this is providd or added last to thc aggcgatc wcish
hopper, io accordance with the job mix formula proportions

The bot binder shall bc *righed out into the binder rvcigh buckct in accordancc
with thc proportions prcscribcd in the job mix formula.

Th"-ttot 3gp€gates and fillcr shall bc discharged Into the pugrnill and nixcd
dry for the dry mixing tirne prescribcd in tha job mix foirnlrh, which shall
usually bc in the rangc 5 to l0 scconds The h& bindcr shall thcn bc addcd
and wct q5ing ggJformgd-for rhc rct mixing tinic prcscribcd in thc job mix
formula; this shall be suflicicnt so that alt particles oi aggregatc arc uniformty
coated with bitumeq and shall usually bc 45 scconds orilorl for densc graded
mildures.

The volume of each batch shall be such that the tips of the pumlill oaddlc
bladcs just breal.out of rhe mi:durc at the hcight oi their actioi

After the complction of wct mixing each batch of asphaltic concrctc shall bc
discharged from the pugnrill either into a storage hopftr or direclly into a trucl
tor hautrng to thc paving site. Care shall bc talcn that no segrcgation of thc
mrx occurs.

Mixing in Continuous Mix Plants

The screcned hot aggrcgates and filler shall be fed continuously from their
storagc b_ins in accordance vith thc proportions prescribed in thaappropriatc
job qir formul4 combined in the piant, and fed continuously into iic iixcr.
The ho_r binder shall be sprayed orto thc combined agregaicas it cntcrs thc
pugmrll at the-rate required to achievc the bitumen contcnt prcscribcd in thc
job mix formula. Thc matcrials shall then bc caricd througli thc pugnill and
in the proccss be thoroughly mixcd by the action of thc paddl-es and dfuharccd
over the dam into thc sroragc hopper. Thc mixing timc (as dclincd in S-ub
Section 4..2.4.4 OD shall be as prcscribcd in rhefob mix'formula; this shall
be sufficicnt so that all particles oI ryregate arc uniformly c&tca witt
bitumen, and shall usually be 45 sccondJ or morc for densc grided mitrurcs.

The plant shall bc so-adjusted as to maintain rhe level of mirurc in thc pugnil
such- that thc tips of the paddle blades just break out of the mirurj ai ttc
height of thcir acrion.

(f) Tnnsponation olAsphatticConcrctc

Asphaltic concrete shalt be transported from the mixing plant to thc sitc of thc
paving works in loads of not less than 5 tonnes using tlptrucks as spccified ir

s+32
 (IKR/SPJ/1e88)

Subsccion a.24.4 (c). Exccpt whcrc asphdtic conctete is to bc band lEi4 it

shalt bc discharged directly into the paver hopper, as rcquird from the tip
trucks. Carc iirdt be taiken in thc truct loading hauling and unloading
opcrations to prevent scgegation of the mix. During transportatioo' tbc
asphdtic concrete shalt bc protected from contamination by satcr' dusl' dlrl
aoi other deleterious matcrials.

Thc tcmDcrature of asphaltic concrctc imnediately before unloading fron thc

truck citircr into tbe piver hopper or on to the road for hand spreadfurg shall
bc not le.ss than f25
oC. n-ny load which has cooled below thc spccified
tcmp€raturc in thc trucl shall bc rejecred for use in the Worls and rcrnoved
from tbe Site of tbe Works.

O laing AsPhaltic Concnte

T'lre sequence of layrng operations shall be planned in adrrancc by- tbc

Co*racior and appr6r,el by the S.O. Generally cach plving.laycr slrall haw
a compactcd thidlies of n6t less than twicc the nominal maximumaggrcgatc
sizc oi tbe mircurg and not morc than tfl) mm. Wherc applicablg,,-c.g -on
supcrclc'iated sections and on carriagewa-5 with e<(s-slopc in olc dircctiol
tavloc shall commence along ihc lwr sidc of thc carriageway ald
pt#d ti the higber sidc. l-aying shall not bc canicd out in a dovnhill
"otv.
ilirection along any seclion of road.

As far as is practicable, laying shall be carried out using.a-paver.approrcd by

thc S.O. Uina-cesting ofbiluminous mix on to the machinc fin'shcd surfacc
shall bc tept to tbc piacticabte minimum nqcessary for-corrccting blcnishcs
areas inacce.ssible to tbc pavcr, laying shall bG cardcd
and incnrtiritics. ln any-using
out by Iand metbods rakeg tutcs and othcr hand tools' all to thc
satisfacion of the S.O. All laying of bituminous mix sha[ bc such tb.t aftct
compaction bry ioline thc specihcd coursc or layer thictness and surfacc prolilc
shall'bc achici,ed. Care striU Ue talen to achierrc a uniform surfacc tcturc frcc
from indentationc ridSec tear mark or other inegulariticg and to prcrent
ccgrcgatioo of tbc mir

Al thc commcnccment of initial rolling the tempcraturc of asphaltic coolT,et9

oC.
shall bc not tess thatr 110 Material which [as cooled belov thc spccified
tcnpctatutc before laying slrall not bc used and shall be rsmored frm thc Site
of tic Worls. Thc Conlractor shalt providc accurate thcrmomctcn at thc
paving sitc at all times, aad shall cbeck the ternpcraturc of asphaltic -coocrctc
io thc-patct hopper ai rcarlar iotervals and beforc laying restarts aftcr cach
intcmrption of thc paving opcration.

As far as is practicable, the pavcr shall be operatcd continuously and thc sup^ply
of bituninbus mix shall be rcgulated so as to enabte cootinuo5 pavin&
Tren-sncrse joints in a paving lane shall bc kept to a practicablc minimum, and
intermitleil stopping ind rl$arting of tbc plrcr shal be awided as frr as is
pradicable.

Carc shall bc tatcn that no biturninous mix is placed on qpension joints at

bridg"c inspcaioo covers for utilities ductg drainag-e ard- se*cragc n-hol9"
and-thc.likc, and that catchpits, drainagc opening through kerbs,-ctc' remain
p'ropcrb open and scrviccablc. During lafng operatiotls, such-arcas and
;p&irit siatt Uc protccte.d by suitably ihaicd and seored boards or othcr
.itdits approrci by the S.O, and iompaoion of mix in thc funrncdiatcly
surroundin!-or adjacent areas shall be cornpletcd by hand methodg dllq thc
setisfectioi of tlie S.O. Alternativcly, bituminous mix shall bc hkl and

s+33
 (JKR/SPJ/re88)

compactcd by hand mr:th()ds as ncccssary around surfacing disconlinuities o[

lhcse lypcs, all to lirc si.rt i:'f.rcl i()n of thc S.O.

(h) Cotrs!ru<tiott toints

Existing bituminous surfacing which ncw bituminous mix is lo adjoin shall be

cut ba(:h t(r prcscnl a straight, vcrtical cdgc nrrl lcss than 25 mm dccp and a
smooth transitron scclion not less fhan 0.5 mctrc long against which to lay the
new matcrial. The specilicd thickness of thc ncw surfacing shall bc built up
grad.ually froni thc vurtical .i(,int lo avoid any bumps or ridges across lhc
csrnagcway.

Whcrc krngiturlinul or transvc:rsc joinls aru rcquircd in a layor of bituminous

mix undcr ci)nqlluction, thc matcrial first laid and compaclcd shall bc cut back
to a vcrtical flcu frrr thc full thickncss of thc laycr on a linc satisfactory to thc
S.C). bcforc thc adjuccnl arca.is pavcd.

At all construction joints, a thin unifirrm coating of bitumcn cmulsion of gradc

RS-l or RS-lK shall bc brushcd on to thc vcrtically cut joint faccs some l0 to
15 minutcs bcforc laying thc ncxt soction of bituminous mix commcnccs lo
cnsurc gtxrd bonding. Also, all conlacl surfaccs of hcrbs, gutlcrs, manholcs,
catchpits, ctc., shall bc sinrilarly trcatcd with a coaling of bitumcn cmulsion
bcforc: hituminous mix is placcd against thcm.

Conslruction joints in a laycr of bituminous mix shall bc offsct from lhosc in

any immcdiatcly undcrlying bituminous layer by at lcast l0() mm for
longitudinal joints and at least (1.-5 mclrc, wherc possihle, for transvcrsc joints.

(i) Ct:ntpaclion ol Asphultic Concrete

For each laycr of asphaltic concrcte, compaction by rolling shall commcnce as

soon after laying as the matcrial will support thc rollcrs without unduc
displacemenl; ncverthclcss lhc tcmpcraturc of asphaltic concrctc at thc
oC.
commcncemcnt of rolling shall lrc not less than ll0

In any areas inacccssible to lhe rollcrs, proper compaction shall bc carricd out
using vibrating plate compactors, hand tampers or othcr suilablc mcans, all to
the satisfaction of the S.O.

Initial (or breakdown) rolling shall be carried oul with an approvcd stcel
wheeled tandcm roller or three wheeled steel tollcr, The principal heavy
rolling shall be carricd out with an approved pneumatic tyred roller
immediatcly following the initial rolling; thc pneumatic tyrcd roller shall be
15 tonncs and its tyre inflalion
lallastcd lo an opcrating weight of not less tban
pressurc shall be not lcss than 0.7 N/sq.mm, The final rolling shall be carried
out with an approved stccl wheeled tandem roller and shall serve lo eliminate
minor surface irrcgularities left by thc pneumatic tyred roller.

All rollcrs shall operate in a longitudinal dircction along the carriageway with
thcir driven wheels towards the pavcr. Rolling shall generally commence at
thc lower edge of the paved width and progress uniformly to the higber edge,
except that whcre iherc is a longitudinal construction joint at the higher edge,
this shall be rolled firsl ahead of the normal pattern of rolling. Generally,
succcssive roller passes shall overlap by half the wrdth of the roller, and the
points at which thc roller is reversed shall be staggered. However, when
operating on gradicnts in excess of 4Vo, the breakdown roller shall not pass
ovet any prcviously unrolled mix when operating in the dowirhill direction.

s4-34
 (JKn/SPJ/le88)

ln all cascg compaction shal bc carricd out in such a matner that cach scction
rcccircs cqud compactive effort, all to thc satisfaction of tbe S.O'

Tbc stcel wheeled rollers shall operate at speeds of not more than 5 Lm/hr
and tbc pneumatic'tyred rollers shall operate at specds ofnol rnorc than
8 fn/hr.- No roller or bcarry vehiclc shall bc allowed !o stgnf on ncwly- hftl
bituniinous mix beforc compaction has been completed and thc qraterial bas
thoroughly cooled and sct. Rolliag shall coltinue as long as is necessary to
achicve thc appropriatc rcquirement as follows r
T}?e of Pavemcpt layer Required Cqmpac'ted Pensity

Wcaring course 9f! - LWTI Mushall dcnsitY

Binder coursc 95 - L00Vo Marshall densitY

Care shall be taten to prewnt over-compaction of asphaltic concreto.

Within 2{ hours of laying and compaaing tbe bituminousmilr, ihe Coitractor

shall cut corc sarnplcs of not less than lfi) mm nominal diametcr at locations
sclectcd by the S.O. Tte ratc of sampling shatl lr I sample -per 5(X)- sq.m. of
nh lai4 but not lcss thao 2 samples for the work complcted in cach paving
scssioo.' Thesc core samptes sh'dl be uscd by thc S.O- to detetminc thc
thictness of the compacted laycr of mix and the compactcd density of thc
matcrial in acmrdancc with either ASTM Te.st Method D 1188 or ASTM Tcst
Method D zTN, whichorer is applicable.

() Finished Asphaltic Conaetc

Asphaltic concretc binder and wearing courses shall be finished in a neat and
*oitmalite oatrner; thcir widths shall bc eve4T vlrere at least thoee specilicd
or shown on thc Drawings on both sides of thc centre-line;' lhc everagg
thickncss over any lIX) metrc lcngh shall bc not lcss than thc rcquired
thidknes$, and thc-minimum thickncss at any point shall bc not les than thc
rcquircd thiclness minus 5 mm.

Thc t@ surface of a wcaring or binder course shall have the requircd shapc,
supcreicvation, levels and gradeq, and shall be everywhere within the tolcrances
spccified in Sub-Section 4.4.

(r) Opcni"S to Tmfic

Asphdtic coqeretc shall not bc opcned to traffic until compaction has leen
coinplctcd end thc material has thoroughly coolcd and sel in thc opinion of the-
S.O.: This will usually be not less than 4 bours after the comnicoccmcnt of
rolting Wbere it is neccssary to allow earlier usc- of thc finished surfacc
to fadlitatc tho movernent oltrafliq whides may bc allowed to run on thc
work aftcr rolling has bcen completid ppvided that sPecdl are restricted
to 30 kn/br or less and sharp turning mbvcnren(t arE Prohibiled.

s+35
 (JKR/SPJ/re88)

4.2.5 Bituminous Macadam

4.2.5.r Dcscription

This work shall consist of furnishing placing shaping and compacting

bituminous macadam roadbase and/or levelling course and/or binder course
and/or wearing course on a prepared and acceptcd biiuminous or biturnen
princd pavemCnt course, and shall include the careful and thorough cleaning
of surfaies which are lo be covcred without recciving a bituminous tact coat.
The work shall be carried oul all in accordance with this Spccification and the
lines, lcvcls, gradcs, dimensions and cross-sections shown on the Drawings
and/or as required by the S.O.

4.2.5.2 Matcrials

The matcrials for biluminous macadam (aggregates, mincral filler, bituminous

bindcr and anti-stripping agent) shall comply with all thc requirements of Sub'
Section 4.2.4,1 exccpt for the combined gradation requitements.

For each bituminous macadam mi:q the gradation of thc combined coarsc and
fine aggrcgatcs, together with ordinary Portland ccmcnt added as an adhcsion
and anti-stripping agent and, if necessary, any other mineral fillcr' shall
conform to the appropriate eovelope given in Table 4.12. The binder content
shall also bc in accoidance with Table 4.12.

Where lhe characteristics ofthe aggtegates require a bindcr content other than
that given in the above Table, the revised target binder contcnt shall bc agrced
bctwccn thi Contractor and thc S.O. and the same tolerances shall apply.

4.2.5.3 Equilnrent

Tlre equipment shall bc all as specified in Sub-Section 4.2.4.4.

4.2.5.4 Construction Mcthods

All the provisions ofSub-section 4.2.4.5 for the construction of asphaltic

concrcte pavement courscs shall apply as appropriatc to the construction of
bitunrintrus macadam pavement courscs with the following variations and
addit' 'ns,

(a) Agyegate Heating

Thc aggrcgatcs shall be dried and heatcd so that when delivered to thc mixer
oC to 160 oC.
thgy shall bc at a tempcrature in.the range 1rl0

(b) Rolling Tempemure

The tempcrature of bituminous macadam at the commencemcnt of rolting shall

bc not liss than 100 oC.

(c) Contpocred Density

The compacted dcnsity of bituminous macadam shall be as follows :-

s4-36
 (JKR/SPJ/1e88)

Tyoe of Pavement Laver Required Comgacted Dcnsitv

Bound roadbase 9O - lffiVo Marshall density

I-evelling coursc 9O - lffiVo Marshdl density
Binder course 95 - Iffi% Marshall density
Wearing course 98 - l@Vo Marshall density

The Marshall density of a bituminous macadam mix is delined as the avcragt

density of a set of threc test spccimens moulded in.the -same way as asphaltic
.orr.tit" specimens are preparcd for tbe standard stability _and flow tcst itr
accordance with AASHTO Test Method T 245 using tbc 75 blo*: pcr facc
compaction standard. Thc bulk spccific gravity o{ thc spccimens slnll bc
deteimined in accordance with AASHTO Tcst Mcthod T 166.

The Marshall density of each mix shall be determined using a samplc (o1
samples) taken from the mixing plant soon after the commcnccment of
preparing each mix for the Works.

(Note : Stability and flow tests arc not normally required for bituminous
macadam mixes.)

(d) Finished Biuminotts Macadam

Bituminous macadam roadbase shall be finished in a neat and workmanlikc

manner; its width shall bc cverywhere at least that specihed or shor,n on thc
Drawings on both sidcs of the ccntrc-line; and its averagc thickness ovcr _any
100 metie length shall be not less than tbe required thickncss. Thc top surfacc
of bituminoushacadam roadbase shall have thc required shapc, superclcvatioq
levelb and grades, and shall bc everywhcrc within the toleranccs spccificd in
Sub-Scction 4.4.2.

Bituminous macadam levelling course shall bc finished in a ncat and

workmanlike manner; its dimensions shall be as spccilied or shown on tbc
Drawings or as direcled by thc S.O,, dl to the satisfaction of the S.O' Thc top
surface bf bituminous macadam levelling coursc shall have the required shapc,
superelevation, levels and gradeg and shall be everywhere within the toleranccs
for binder course specified in Sub-Section 4.4.

Bituminous macadam bindcr and wearing oourses shall bc finished io a ncat

and workmantike manner; thcir widths shall bc eveqvhere at least thocc
specilied or shown on the Drawings on both sides of the ccntre-linc; thc
average thickness ovor any 100 mctre length shall be not less thanthe required
thickness, and the minimum thickness at any point shall be not less than the
required thickness minus 5 mm. The top surface of a wearing or binder course
shall have the required shapc, superelevation, levels and grades, and shall bc
everywhere within the tolerances spccified in Sub-Section 4.4.

s+37
 (JKR/SPJ/1e88)

TABLE 4.I2. GRADATION LIMITS AND BINDER CONTENTTI

FOR BITUMINOUS MACADAM

Mir Typc Bound Bound Levclling Bindcr Bindcr Wcrrint Wcrring

Ro.dbrEG Ro.dbrsc Coursc Cou't3 Coorta C.ourrc C.outrc

Mir Dcsignation BMR4{) BMRzE BMLIO BMB28 BMB:N BMTY1' BMTV:IO

B.S, Tcst Sicw % Pessint By Wsitht

50.0 mm lo
nS mm 95- tm tq) lm
28.0 mn m- 9l s- tm 90. tm qt-ft r;1
1).0 mn 7l- % 7t- 95 lm 1m 9J.lm
14.0 mrn 5ri - 76 56- g) l(p 56- g2 65- 85 95- tm 65- 85
10.0 mnr 8J.lm s2- 72 m- qt 52- n
6.3 nm u- o 4- 60 1)- fi u- fr 39- 55 15- 6t 9- 55
3.35 mm 32- # 3l- 45 15- 25 n- $ n- 6 30. /|:' n- $
l.l8 nm l:t- :n
3m um 7- 21 7- 2r 7- 7- 21
21 7.2r
75 um 2- 8 2- t 2- 6 2- t 2. 8 3- ? 2- t
Bindcr Contcnl ts !05% 1,0 3OS7c S.l + 0Sq, 4.7 JO.6% 1,7 + 0.6% 5.0 !05% +9 Jisqo

s+38
 (JKR/SPr/te8t)

4.3 SHOT]LDERS

4.3.1 Description

This work shall consist of furnishing compacting and shaping carth or gravcl
shoulder material on a preparcd and acccptcd subb$g or lowcr cubbasc
q
subgrade, alt in accordance with this Specification and tbc linc$' lffils' gradan
diminsions and cross-sections shown bn the Drawings and/or as requircd by
the S.O.

For oaved sbouldcrs. tbe bituminous surfacitg and undcrlying pawmcnt counscs
sUi Ue construcled as describcd in thc appropriate Sections of lhil
Spccification.

4.3.2 Materials

4.32.1 Earth Shoulders

Earth shoulder matcrial shall be suitable rnatcrial as dcscribcd io

SubSection 2.2.1.

4.3.2.2 Gravel Sboulders

Gravel shoulder material shall conform to the requircments for gravcl surfacirg
material set fortb in Sub-Section 4.1.3.2

43i Construclion Methods

Sbouldcrs shall be construcled in stages or in one operation as diic.lcd or

aooroved by the S.O.. but in no instancc shall a shouldcr bc built up to a lorcl
hidher thari that part of the abutting carriagcway structurc which has bccn
completed and accepted.

Prior to placing any shoutder malerial, the,undcrlying subbasc or lowpr subbasc

or subgr:adc tf,"['h"t" been sbapcd and compiaed.in accordancc with thc
provisions of Subscction 4.1,23, andrhe abutting carriagcway structurc coutrc
br courscs shall litewise have been shaped and conrpaacd in accordancc with
thc provisions of tbc appropriate Subscctioo or Sub-scaions of this
Speci:fication. ttotwithstiniin! any earlier approval-of thc undcrlying-end
a6utlinc paycment @urses, any darnagc to ot dcterioration of
tbcsc
underlfrn! and abuttin! pavement courscs slrall bc made good to thc
satisfaition of the S.O. beiort shoulder construction procccds'

Shouldcrs shall bc placcd ro the requircd width and thickness as shown on ths
Drawings or directed by the S.O. in one lapr ot morc,.cach layt-r not
cxceediig 200 mm compaacd thickness at thg Pgint of maximum thictrcss'
Whcrc tio or more layers arc rcquircd tbcy shall bc of approrirn{gly gqual
sbapc and thickncss" and none shall be less than 100 mm compaclcd thidncss
at the point of maximum thickncss.

Each layer of shoulder material shall bc procassed as necessary to- b-rr18 -its
moisturl content to a uniform tcvcl thrbughout tbe matcrial suitablc for
compactioq and shalt then bc compacted using suitable compaction cquipmcnt
apprbwd by the S.O. to not less t\an 95% of the maximum dry douity
dliermined- in the B.S. 137 Compaction Test (4.5 kg rammcr merhd).
Compaction shall bc carried out in atongitudind dircuion along thc shouldcr

s4-39
 (JKR/sPJ/1%8)

and shall generally begin at the outer edge and progress uniformly towirrds thc
carriageway, except on superelevated curves where rolling shall begin at lo*er
edge and progress uniformly towards the higher edge. In all caseg compactiotr
shall be carried out in such a manner that each sectioa receives compactirrc
effort appropriate to its thickncss, all to the satisfaction of the S,O,

Throughout the placing adjustment of moisture content and compaction of

shoulder material, care shall be taken to maintain a uniform gradation of the
material and prevcnt its seperation into coarse and scpcratc parts, dl to the
satisfaction of the S.O.

Where shown on the Drawings or directed by the S.O., earth shoulders shall
bc turfed in accordance with Sub-Section 2.2.8.2.

Shoulders shall be finished in a Deat and workmanlike manner. The total width
of carriageway and shoulder shall be everywhere at least that specified or
shown on the Drawings on both sides of thc centre-line. The top surface of
each shouldcr shall have the required shapc, supe.relevation, levels and grades,
shall be cverywherc within l0 mm of the required plane, and shall providc a
flush joint with the carriageway surface and shall be uniformly free draining
away from the carriageway, all to the satisfaction of the S.O.

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 (JKR/SPJ/1e88)

4.4 nonrzoNTAl ALIGNMENI, SUnFACE LEVEI,S Al{D

SUNFACE REGUI,ARITY OF PAVEMEM COURSES

4.4.1 Horizontal Aliqnment

The horizontal dignme* shall bc deternined from thc centre'linc of thc

Davement surfacc ibown oo thc Drawings. The edges of tbe pavement as
ionstructed and all other parallel construclion lires shall bc correct within a
tolerance of + 50 mm and minus 0 mm from the centrc-line, cxcept for
ker\ channel block and edgc linas which shall be laid with a smooth
aligrmeot within a tolerance of-+ 25 mm and minus 0 mm from the ccntrc'
line.

4.4.2 Surface Lcvels of Parrcmcnt Courses

The dcsign levels of plvement courses shall be calculated from thc vertical
orofile. cr-ossfall and drement course thicknesses shown on the Drawingp. Thc
ievel oi any point o*ihc construded surfacc of a pavernen! 99Jlf shall bc thc
design level-subject to thc appropriate toleranccs given in Tablc 4.13.

TABLE {.13 . TOLERANCES IN SURFACE LEVEIII OF

PAVEMENT COURSES

Pavement Course Tolerance

Wcaring Coursc + 5mm

Binder Course + 5mm

Roadbasc + 0mm
-a)mm

Subbasc and Lower + l0mm

Subbasc -20mn

Tbc comtrination of pcrmittcd tolcrances in the lcvcls of dillcrent pavcmel

oourses shalt not result in a Pavcment thickness less than that sho*l on the
DrawingS. Each pavcment course shall havc an average thitkness nOt lcss than
that shown on the Drawings.

4.4.3 gUrface Regularity

Thc regularity of surfaccs shall be within the relevant limitS givar in Table 4.14.

A longitudinal irrcgularity is a rrariation in prolile of the road surfacc as

rneasuicd by the roiling stiaight-edge or wedgC and straight-edgc device. Thc
permissiblc number of Iuch longitudinal irregulariries is indicated in Tablc 4.14.

The traversc length of 3(tr rn and its associated maximum permissiblc nu3bc1
of irregularitics Jha[ apply whcrevcr the continuous length of the completed

s+41
 (JKR/SP'/leqB)

carriageway is 300 m or more, whether or not it is constructed in shorter

lcngths.

Where the total length of pavement is less than 300 m the measurements shall
bc taken on 75 m lengths.

The transvcrsc regularity of a newly laid surface shall be measured with a 3 m

straight-edge aad shall bave no great* depression under the straight-edge than
that shown in Tablc 4.14.

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 (JKR/SPJ/1988)

TABLE TOLENANCES| FOR SUNTACE INNEGT'I"ARITIES

'.T4.

Maxinun Pcrniaerlblc Numbcr Meriuun

of Surfacc Incgulariticc PcTDLdHG
Class of DGpl[ of
Surfacc Trrnrrrrrc
Rcgularity Dcpth Excccding 4 mm Ihptb Excccdiag 7 nn brofuluittcr

ol/er ovgr oycl ovgr

trawrsc tn|vcrac trtvcrto trtYrcr8c
length lcngth lcogth lcngth
of 3fl) m of 75n of 3fl) m of 75m

m 9 2 I 4mn
40 18 4 2 tmn
@ n 6 3 lil mn

No lomitudinal irrcrutarity clc6cdinS 10 mm shall bc pcrnitted for Ctrsr SRI Surfacc

ncgutaf;ty and no tdogitudinal incgrrlarity etceding 15 nn sbdl bo pcrrnittcd for Clarc
SR2 rnd Class SR,3 Surfacc Rcgulsritia

Thc class of SurfaCc Rcgrlarity for cach portion of thc Worls shdl bG ac ltrt€d oo thc
Drawingr or in thc Bilr of Quantitics.

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