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CRUSHING IMPACT ABRASION
TEST TEST TEST
SOUNDNESS
SHAPE TEST
TEST
CRUSHING i) The aggregates passing through
TEST 12.5mm and retained on 10mm IS
Sieve is filled in cylinder in 3 layers,
each layer tamped with 25 strokes
This test is usedto ii) The weight of aggregates is
find strength of
aggregates measured (Weight 'A').
WATER SPECIFIC BITUMEN iii) The surface of the aggregates is
AGGREGATE then levelled and the plunger
ABSORPTI GRAVITY ADHESION CRUSHING VALUE
ON TEST TEST TEST = B/A *100 inserted. The apparatus is then
placed in the compression testing
SURFACE COURSE machine and loaded at a uniform
ACV value should not rate so as to achieve 40t load in 10
exceed 30%
minutes. After this, the load is
BASE COURSE ACV released.
value should not exceed
45% iv) The sample is then sieved through
a 2.36mm IS Sieve and the fraction
passing through the sieve is
weighed(B)
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IMPACT TEST
SIZE OF AGGREGATE = 10
TO 12mm THE TEST IS PERFORMED ON
WEIGHT OF HAMMER = IMPACT TESTING MACHINE.
13.5 kg to 14kg
HEIGHT OF FALL = 38cm
NUMBER OF BLOWS = 15 Procedure is same as crushing
AGGREGATE IMPACT value test instead here impact is
VALUE = B/A * 100 done by hammer with a certain
height ,15 number of times.
SURFACE COURSE value
should not exceed 30%
WBM value should not
Thereafter crushed aggregate is
exceed 40%
sieved through 2.36 mm sieve.
ENERGY= 15mgh
It is used to measure wear and tear and is
ABRASION TEST best test of aggregate which includes
abrasion( rubbing between aggregate
LOS ANELES and steel ball), attrition (mutual rubbing
ABRASION TEST between aggregate) and impact.
NO. OF REVOLUTION T es t c ons ist s o f holl ow cyli n der clo sed a t
= 33rpm upto 500 both end s i n w hic h charg e is po ured a n d
revolution. then it is rotated with specified speed.
During rotation all the three action takes
SIEVE SIZE= 1.7mm place abrasion, attrition and impact.
ABRASION VALUE The results is passed through 1.7 mm
= B/A *100 sieve
SURFACE COURSE B= weight of aggregate passing 1.7mm
value should not exceed sieve
30% A= total weight of aggregate
BASE COURSE value Coefficient of hardness = 20 – loss of wt.
should not exceed 50% in gm/3
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SOUNDNESS Clean , dry aggregates is immersed in
TEST saturated solution of sodium
sulphate or magnesium sulphate.
Soak specimen for 10 – 16 hrs.
Soundness test is done Dry it at 105 Oc
to study the resistance of
Repeat for 5 cycles
aggregate to weathering
action by conducting
accelerated weathering With sodium sulphate
test cycle. - loss in weight should not exceed
12%
It is test for
DURABILITY. With magnesium sulphate
- loss in weight should not exceed
18%
FLAKINESS INDEX Size of aggregate > 6.3mm
ELONGATION INDEX Aggregate is passed through slot from
ANGULARITY NUMBER thickness side
Flakiness index is the % by weight of aggregate
whose least dimension is less than 0.6d
d= mean size
FI = B/A *100 should not exceed 15%
A= Total weight of sample
B= weight of aggregate passing thickness gauge.
Size of aggregate >6.3mm
Elongation index is the % by weight of
aggregate whose greatest dimension is more
than 1.8d
d= mean size
EI = B/A*100 should not exceed 15%
A= total weight of sample
B= weight of aggregate retained on length gauge
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• A.N. = 67- Wa /WwG
A.N.= 67% - %solid volume Wa = wt of aggregate occupying cylinder
where 67%= % solid volume of most Ww= wt of water occupying same volume of
rounded aggregate in well compacted state. cylinder.
• It measures voids in excess of 33%. G= specific gravity of aggregate.
• G=¥ a /¥ w = Wa V w/V a Ww
V a /V w= Wa /GWw = Va/(Va+Vv)%
=%solid volume
Water absorption should not be more than
0.6% of the weight of aggregate.
Property of Type of Test TestMethod
aggregate
Crushing strength Crushing test IS : 2386 (part 4) -
1963
Hardness Los Angeles IS : 2386 (Part 5)-
abrasion test 1963
Toughness Aggregate impact IS : 2386 (Part 4)- PENETRATI DUCTILITY VISCOSITY
test 1963
ON TEST TEST TEST
Soundness test- IS : 2386 (Part 5)-
Durability accelerated 1963
durability test
Shapefactors Shapetest IS : 2386 (Part 1)- SPECIFIC
1963 FLOAT
GRAVITY
Specific gravity Specific gravity IS : 2386 (Part 3)-
TEST
and porosity test and water
absorption test
1963 TEST
Adhesion to Stripping value of IS : 6241-1971
bitumen aggregate
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Itrepresent hardness or softness of bitumen by
measuring the depth in one-tenth of mm to
SOFTENI FLASH SPOT which a standard needle carrying a weight of
NG AND FIRE TEST 100g penetrates in 5 sec at a temp of 25 Oc.
POINT POINT Ifgrade of bitumen is 80/100, then the
TEST TEST penetration value lies between 8 to 10mm.
Tars are soft hence penetration test are not
used.
Grade of bitumen is decided on the basis of
penetration test.
S- 30 it means bitumen is manufactured from other
source
It is the distance in centimeters to which a
standard briquette of size 10mm x 10mm can
be stretched before the thread breaks at a
standard temp of 27 Oc.
It is a measure of adhesiveness and elastcity of
bitumen.
A minimum ductility value of 75 cm has been
specified by the BIS.
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It is inverse of fluidity and it is measure of
resistance to flow.
It is the time taken in seconds by 50ml of
material to flow from a container through a
specified orifice of size 10mm under standard
test and temperature(25 oC)
At low viscosity the bitumen binder simply
lubricates the aggregate particle instead of
binding.
At high viscosity it will resist the compactive
effort but mixture is heterogeneous.
Normally the consistency of bituminous Time required for water to pass its waythrough
material can be measured either by penetration the specimen plug is noted in seconds and is
expressed as the float value.
test or viscosity test.
It is used to measure consistency of material for
which penetration and viscosity test cannot be
used.
Bitumen cooled at 5 oC put
bitumen in aluminium float and place it in
water at 50 oC find out time taken by
water to inject through bitumen
FLOATVALUE
HIGHER THE FLOAT VALUE STIFFER IS
THE BITUMEN
The specific gravity of bitumen is defined as the
Softening point is the temperature at which
ratio of mass of given volume of bitumen of
bitumen attains a particular degree of
known content to the mass of equal volume of
softening.
water at 27 C.
Higher softening point means lower
The specific gravity can be measured using
temperature susceptibility and is preferred in
either pycnometer or preparing a cube
warm climate.
specimen of bitumen in semi solid or solid
state. Softening point lies between 35oC to 70oC.
Pure bitumen = 0.97 to 1.02
Tar = 1.10 to 1.25
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FLASH – it is the temp. at which bitumen
vapours momentarily takes fire in the form of
flash. Standard flash point according to IRC is
175oC.
FIRE POINT- it is the lowest temperature at
which bitumen gets ignited and burned
APPARATUS- Pensky martin closed & open
cup apparatus
To check whether Bitumen is cracked or
uncracked.
Take 2gm of bitumen + 10 gm of naptha.
Pour it over filter paper
If uniform colour appears throughout then
bitumen is uncracked.
If dark brown color at center and uniform
color at outer side then bitumen is cracked.
The distillates used for preparation of cutback bitumen
Cutback bitumen :- are naphtha, kerosene, diesel oil, and furnace oil.
Normal practice is to heat bitumen to reduc e its
There are different types of cutback bitumen:
viscosity. In cutback bitumen suitable solvent is •rapid curing (RC),
used to lower the viscosity of bitumen. • medium curing (MC), and
•slow curing (SC).
The solvent from the bituminous material will
RC is recommended for surface dressing and
evaporate and the bitumen will bind the patchwork.
aggregate. MC is recommended for premix with less quantity of
Cutback bitumen is used for cold weather fine aggregates.
bituminous road construction and SC is used for premix with appreciable quantity of fine
aggregate
maintenance.
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•
Bitumen Emulsion:
Three types of bituminous emulsions are available,
•Bitumen emulsion is a liquid product in which bitumen is
• Rapid setting (RS),
suspended in a finely divided condition in an aqueous
• Medium setting (MS), and
medium and stabilised by suitable material.
•Slow setting (SC).
•Bitumen emulsions are ideal binders for hill road
•Normally cationic type emulsions are used in India. The
construction Where heating of bitumen or aggregates
bitumen content in the emulsion is around 60% and the
are difficult.
remaining is water. •Rapid setting emulsions are used for surface dressing
work.
•When the emulsion is applied on the road it breaks down
•Medium setting emulsions are preferred for premix
resulting in release of water and the mix starts to set.
jobs and patch repairs work.
•Slow setting emulsions are preferred in rainy season.
• The time of setting depends upon the grade of bitumen.
Bituminous primers
In bituminous primer the distillate is absorbed by the
road surface on which it is spread. Modified Bitumen
Certain additives or blend of additives called as bitumen
The absorption therefore depends on the porosity of the modifiers can improve properties of Bitumen and
surface. Bitumen primers are useful on the stabilised bituminous mixes.
surfaces and water bound macadam base courses. Bitumen treated with these modifiers is known as
modified bitumen. Polymer modified bitumen (PMB)/
Bituminous primers are generally prepared on road sites crumb rubber modified bitumen (CRMB) should be used
by mixing penetration bitumen with petroleum distillate. only in wearing course depending upon the requirements
of extreme climatic variations.
It must be noted that the performance of PMB and CRMB
is dependent on strict control on temperature during
construction
Grades of road tar as follows: RT-1, RT-2, RT-3, RT-4,
RT-5
BITUMEN TAR
RT 1 has lowest & RT 5 has highest viscosity .
Fractionaldistillation of Destructive distillation
As number increases viscosity increases
petroleum of coal.
Low Temperature Hi gh T em perat ure RT 1 :- for surface painting under exceptionally cold
susceptibility(less effect sus cepti bility( more weather conditions and on hill roads.
of change in temp.) effect) •RT 2 :- standard surface painting under normal
Soluble in carbon Soluble in benzene or Indian climatic condition.
tetrachloride toluene •RT 3 :- surface paintings,renewal coats,premixing
chips for top course.
•RT 4 :- premixing tar macadam in base course.
•RT 5 :- for grouting.
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MASTIC ASPHALT Mastic Asphalt
Mastic asphalt is basically a composition of suitably graded
mineral matter and bituminous cement in such proportion as
t form a coherent, voidless and impermeable mass. Mastic asphalt / bitumen mastic as an overlay is
dustless, odourless, jointless and is impervious to the
It is hard at normal temperatures, but sufficiently fluid when transmission of moisture either in liquid or vapour
heated at around 180`c for easy spreading by hand tools. form.
Mastic asphalt generally requires little maintenance. In case
of damage or wear on any area occurs it can be easily relaid
Plastic asphalt poured and trawled by hand, has been
and matched to the adjoining area leaving behind a widely used for various purposes.
homogeneo us and jointless surface.
Mastic asphalt has a long and successful history of a
wide range of users as road surfacing medium, bridge
decking layer and traffic junctions etc
7)Which is the best test considered for the
aggregates and why?
8)Which one of the following is not a desirable
property of the subgrade soil as a highway
material? a)Stability b) Ease of compaction
c)Good drainage d) Bitumen adhesion
9)The result of the ring and ball softeing point
test on asphalts is given in terms of
a)viscosity b) time c) flow
d)temperature
