The document discusses several tests conducted on aggregates and bitumen used in road construction. It provides overview, apparatus, procedure and technical discussion for each test. The aggregate tests covered are impact value, crushing value, flakiness index, elongation index and abrasion value. The bitumen tests covered are penetration value, ductility, flash and fire point. The tests help evaluate properties like strength, toughness, shape, hardness and temperature susceptibility of materials used in pavements.

2. IMPACT TEST OF AGGREGATE
Overview: The aggregate impact value gives a relative measure of the resistance of an
aggregate to sudden shock or impact, which in some aggregates differs from its
resistance to a slow compressive load. (Reference:
IS: 2386 Part 4-1963)
Apparatus :
 Balance & IS Sieves
 Impact Testing machine
Procedure :
 Take some aggregates passing through 12.5 mm sieve and
retained on 10 mm Sieve.
 Fill the cup of impact machine with aggregates.
 Allow the hammer to fall free on aggregate and apply 15 such
blows.
 Sieve the remaining crushed aggregates through 2.36 mm IS
sieve and weigh the passing material.
Technical Discussion:
 Impact value =
Weight of passing material
Weight of original sample
x 100
Impact Testing Machine
Impact value Toughness Properties
<10 (%) Exceptionally tough / Strong
10 – 20 (%) Very tough / Strong
20 – 30 (%) Good for pavement surface course
>35 (%) Weal for pavement surface course

3. CRUSHING TEST OF AGGREGATE
Overview: The aggregate crushing value provides a relative measure of resistance to crushing
under gradually applied crushing load. (Reference: IS: 2386 Part 4-1963)
Apparatus :
 Steel Cylinder
 Cylindrical metal measure & IS Sieves
 Tamping Rod, Balance & Oven
 Compression testing Machine
Procedure :
 Aggregates passing through 12.5 mm sieves and
retained 10 mm sieves are filled in a cylindrical
measure.
 The test sample is weighed and placed in the test
cylinder.
 The specimen is subjected to a compressive load
of 40 tons gradually applied at the rate of 4 tons
per minute.
 Then crushed aggregates are then sieved through
2.36 mm sieve and weigh the passing material.
Technical Discussion:
 Crushing value=
Weight of passing material
Weight of original sample
x100
 A value less than 10 signifies an exceptionally
strong aggregate while above 35 would
normally be regarded as weak aggregates.

4. FLAKINESS INDEX VALUE TEST OF AGGREGATE
Overview: The flakiness index (FI) is defined as the percentage by weight of aggregate particles
whose least dimension is less than 0.6 times their mean size. (Reference: IS: 2386 Part 1-1963)
Apparatus :
 Flakiness gauge
 IS Sieves
 Weighing balance
Procedure :
 Take aggregates and sieve them through 63 to 6.3 mm IS sieve.
 Find the weight of aggregate of each size.
 Try to pass each aggregate though corresponding slot in the
flakiness gauge.
 Weight all the pieces which passes through the particular slot.
Technical Discussion:
 F.I. =
Weight of the material passing through flakiness guage
Total weight of aggregate
x 100
 Aggregates which are flaky are detrimental to higher
workability and stability of mixes.
Flakiness Gauge
Type of Pavement Maximum limits of Flakiness
Index (%)
Bituminous carpet 30
Bituminous surface dressing 25
WBM base and surface course 15

5. ELONGATION INDEX VALUE TEST OF AGGREGATE
Overview: For determination of elongation index of coarse aggregate, where the size of the
coarse aggregate are larger than 6.3 mm. (Reference: IS: 2386 Part 1-1963)
Apparatus :
 Length gauge
 IS Sieves & weighing balance
Procedure :
 Sieve the aggregates through the sieve set and
determine the weight of aggregates of each
size separately.
 Try to pass each piece through corresponding
gauge size.
 Weight all the material retained by length
gauge.
Technical Discussion:
 Elongation Index =
Weight of the material retained by length gauge
Total weight of aggregate
x 100
 Due to high surface area to volume ratio, the elongated particles lower the workability of
concrete mixes
 Maximum permitted Elongated Index is 35 %, 40% and 45% for aggregate sizes
2 ½’’ to 2’’, 1 ½’’ to ¾’’ & 1/2’’ to 3/8’’.
L e n g t h G a u g e

6. AGGREGATE ABRASION VALUE TEST
Overview: This test determines the percentage wear due to relative rubbing action
between aggregates and steel balls, used as abrasive charge. (Reference: IS: 2386
Part 4-1963)
Apparatus :
 Los Angeles machines
 Cylindrical metal measure
 Tamping Rod
 IS Sieves
 Weighing balance & Oven
Procedure :
 The test sample and the abrasive charge is to be placed in
the machine and rotated at a speed of 20 to 33 rev/min.
 The machine is to be rotated for 1000 revolutions.
 The material is discharged from the machine and separation
of the sample is made on 1.70 mm IS sieve.
 The material coarser than 1.70 mm. IS sieve is washed,
dried accurately weighed to the nearest gram.
Technical Discussion:
Aggregate abrasive value =
Loss of weight due to wear
Original weight of aggregate
x 100
 This test can be executed to test the hardness property
of aggregates and to decide whether they are suitable
either for concrete or road construction.
 The maximum Los Angeles abrasion value should not
be more than 30% for the use of wearing surface and
not more than 50% for the use of concrete.Los Angeles Abrasion Machine

7. PENETRATION VALUE TEST OF BITUMEN
Overview: Penetration value test on bitumen is a measure of hardness or consistency of
bituminous material. Penetration value is the vertical distance penetrated by the
point of a standard needle into the bituminous material. (Reference: IS:
1203-1978)
Apparatus :
 Penetrometer
 Stop watch
 Water bath
 Thermometer, etc.
Procedure:
 Fill the sample into container and keep it into the water bath at 250
C for 1 hour.
 Put the container at penetrometer below the needle.
 Touch the needle to the surface of sample and set the zero reading
of the needle
 Release the needle for 5 second and note the final reading on dial.
Technical Discussion:
 A
80
100
grade bitumen indicates that its penetration value lies
between 80 & 100.
 Grading of bitumen helps to assess its suitability in different
climatic conditions and types of construction.
 For bituminous macadam and penetration macadam, IRC suggests
bitumen grades 30/40, 60/70, 80/100.
 In warmer regions, lower penetration grades are preferred to avoid
softening whereas higher penetration grades are used in colder
regions to prevent the occurrence of excessive brittleness. P e n e t r o m e t e r

8. DUCTILITY TEST OF BITUMINOUS MATERIAL
Overview: Ductility of bitumen is its property to elongate under traffic load without getting
cracked in road construction works. Ductility test on bitumen measures the distance in centimeters
to which it elongates before breaking. (Reference: IS: 1208-1978)
Apparatus:
 Briquette mould
 Ductility machine
 Knife &Thermometer
Procedure:
 The bitumen sample is heated and poured in the mould
assembly.
 The excess bitumen is cut and the surface is leveled
using a hot knife. Then the mould with assembly
containing sample is kept in water bath of the ductility
machine for about 90 minutes.
 The sides of the moulds are removed and the machine is
operated. The distance up to the point of breaking of
thread is the ductility value which is reported in cm.
Technical Discussion:
 Bitumen with low ductility value may get
cracked especially in cold weather.
 Binder material having insufficient ductility
gets cracked when subjected to repeated
traffic loads and it provides pervious
pavement surface.
B r i q u e t t e M o u l d
D U C T I L I T Y M A C H I N E

9. FLASH AND FIRE POINT TEST OF BITUMEN
Overview: Flash and Fire point test is conducted on bitumen to know the safe mixing and
application temperature values of particular bitumen grade. (Reference: IS : 1209-1978)
Apparatus:
 Pensky-Martens closed tester.
 Thermometer
Procedure:
 The bitumen is filled in the cup and heated at the
rate of 50 C to 60 C/min.
 The stirring is done at a rate of 60 revolutions/min.
 The test flame is applied at intervals depending
upon the expected flash and fire points.
Technical Discussion:
 For any type of Bitumen grade:
Minimum Flash point should be = 1750C
Minimum Fire point should be = 1750C + 50C. Pensky-Martens Apparatus
FLASH POINT: The Flash point of a material is the
lowest temperature at which vapor of substance quickly
catches fire in the form of flash.
FIRE POINT: The fire point of a material is the lowest
temperature at which material catches fire and burns.
 At higher temperatures bituminous materials leave out volatiles. These volatile vapors contains hydro
carbons. So, they can catch the fire easily and will cause flash at one point and if it is further prone to
heat the material may ignite and burn