BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG.

, SHEAT - COLLEGE OF
ENGG., VARANASI
Experiment No.1 A

DETERMINATION OF AGGREGATE CRUSHING VALUE

1. OBJECTIVE

1) To determine the aggregate crushing value of coarse aggregates.

2) To assess suitability of aggregates for use in different types of road pavement.

2. PRINCIPLE

The aggregate crushing value gives a relative measure of the resistance of an aggregate to crushing
under a gradually applied compressive load. Crushing value is a measure of the strength of the
aggregate. The aggregates should therefore have minimum crushing value.

3. APPARATUS

The apparatus of the aggregate crushing value test as per IS: 2386(Part IV)–1963 consists of:

3) A 15cm diameter open ended steel cylinder with plunger and base plate, of the general
form and dimensions as shown in Fig 1.
4) A straight metal tamping rod of circular cross-section 16mm diameter and 45 to 60 cm
long, rounded at one end.
5) A balance of capacity 3k, readable and accurate up to 1g.
6) IS Sieves of sizes 12.5, 10 and 2.36 mm
7) A compression testing machine capable of applying a load of 40 tonnes and which can
be operated to give a uniform rate of loading so that the maximum load is reached in 10 minutes.
The machine may be used with or without a spherical seating
8) For measuring the sample, cylindrical metal measure of sufficient rigidity to retain its
Form under rough usage and of the following internal dimensions:

Diameter=11.5cm
Height =18.0cm
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Fig1 AGGREGATE CRUSHING TEST APPARATUS

4. PROCEDURE

The test sample: It consists of aggregates sized 12.5 mm - 10.0 mm (minimum 3kg). The
aggregates should be dried by heating at 100-110o C for a period of 4 hours and cooled.
1) Sieve the material through 12.5 mm and 10.0 mm IS sieve. The aggregates passing
through 12.5 mm sieve and retained on 10.0 mm sieve comprises the test material.
2) Thecylinderofthetestshallbeputinpositiononthebase-plateandthetest sample added in
thirds, each third being subjected to 25 strokes with the tamping rod.
3) The surface of the aggregate shall be carefully leveled.
4) The plunger is inserted so that it rests horizontally on this surface, care being taken to
ensure that the plunger does not jam in the cylinder
5) The apparatus, with the test sample and plunger in position, shall then be placed between
the plates of the testing machine.
6) The load is applied at a uniform rate as possible so that the total load is reached in10
minutes. The total load shall be 40 tones.
7) The load shall be released and the whole of the material is removed from the cylinder
and sieved on 2.36mm IS Sieve.
8) The fraction passing the sieves hall be weighed and recorded.

5. REPORTING OF RESULTS

The mean of the two results shall be reported to the nearest whole number as the ‘aggregate crushing
value’ of the size of the material tested.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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6. CONCLUSION
Aggregate Crushing test value=

Record of Observation

Sample I Sample II

Total weight of dry sample taken

=W1gm

Weight of portion passing 2.36 mm

sieve = W2gm

Aggregate crushing = (W2/W1)*100

Value (per cent)

Aggregate Crushing Mean Value =

BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Questions / VIVA VOCE

1. What is aggregate crushing value? How would you express it?

2. Aggregate crushing value of material A is 40 and that of B is 25. Which one is better and why?

3. What are the recommended maximum values of aggregate crushing value for the aggregates to be
used in base and surface courses of cement concrete?

4. What is the specific standard size of aggregates? How the aggregate crushing value of non-standard
size aggregate is evaluated?
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Experiment No. 1 B

DETERMINATION OF AGGREGATE IMPACT VALUE

1. OBJECTIVE

1) To determine the impact value of the road aggregates

2) To assess suitability of aggregates for use in different types of road pavement

2. PRINCIPLE

The property of a material to resist impact is known as toughness. Due to movement of vehicles on the
road the aggregates are subjected to impact resulting in their breaking down into smaller pieces. The
aggregates should therefore have sufficient toughness to resist their disintegration due to impact. This
characteristic is measured by impact value test. The aggregate impact value is a measure of resistance
to sudden impact or shock, which may differ from its resistance to gradually applied compressive load.

3. APPARATUS

The apparatus of the aggregate impact value test as per IS: 2386 (Part IV)–1963 consists of:

1) A testing machine weighing 45 to 60 kg and having a metal base with a plane lower surface of
not less than 30 cm in diameter. It is supported on level and plane concrete floor of minimum 45 cm
thickness. The machine should also have provisions for fixing its base.
2) A cylindrical steel cup of internal diameter 102 mm, depth 50 mm and minimum thickness 6.3
mm.
3) A metal hammer p weighing 13.5 to 14.0 kg the lower end is cylindrical in shape, is 50 mm long,
100.0 mm in diameter, with a 2 mm chamfer at the lower edge and case hardened. The hammer should
slide freely between vertical guides and be concentric with the cup. The free fall of the hammer should
be within 380 ± 5 mm.
4) A cylindrical metal measure having internal diameter of 75 mm and depth 50 mm for measuring
aggregates.
5) Tamping rod10 mm in diameter and 230 mm long, rounded at one end.

6) A balance of capacity not less than 500g, read able and accurate up to 0.1g.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Fig 2 AGGREGATE IMPACT TESTING MACHINE

4. PROCEDURE
The test sample: It consists of aggregates sized 12.5 mm - 10.0 mm. The aggregates should be dried by
heating at 100-110o C for a period of 4 hours and cooled.
1) Sieve the material through 12.5 mm and 10.0 mm IS sieve. The aggregates passing through 12.5
mm sieve and retained on 10.0 mm sieve comprises the test material.
2) Pour the aggregates to fill about 1/3rd depth of measuring cylinder.
3) Compact the material by giving 25 gentle blows with the rounded end of the tamping rod.

4) Add two more layers in similar manner, so that cylinder is full.

5) Strike off the surplus aggregates.

6) Determine the net weight of the aggregates to the nearest gram (W).
7) Bring the impact machine to rest without wedging or packing up on the level plate, block or
floor, so that it is rigid and the hammer guide columns are vertical.
8) Fix the cup firmly in position on the base of machine and place whole of the test sample in it and
compact by giving 25 gentle strokes with tamping rod.
9) Raise the hammer until its lower face is 380 mm above the surface of the aggregate sample in the
cup and allow it to fall freely on the aggregate sample. Give15such blows at an interval of not less
than one second between successive falls.
10) Remove the crushed aggregate from the cup and sieve it through 2.36 mm IS sieves until
no further significant amount passes in one minute. Weigh the fraction passing the sieve to an
accuracy of 1 gm (W Also weigh the fraction retained in the sieve.
11) Note down the observations in the Performa and compute the aggregate impact value. The mean
of two observations, rounded to nearest whole number is reported as the Aggregate Impact Value.
5. PRECAUTIONS
1. Place the plunger centrally so that it falls directly on the aggregate sample and does not
touch the walls of the cylinder in order to ensure that the entire load is transmitted on to the
aggregates.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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2. In the operation of sieving the aggregates through 2.36 mm sieve the sum of weights of
fractions retained and passing the sieve should not differ from the original weight of the
specimen by more than 1 gm.
3. The tamping is to be done properly by gently dropping the tamping rod and not by
hammering action. Also the tampering should be uniform over the surface of the aggregate
taking care that the tamping rod does not frequently strike against the walls of the mould.
6. REPORTING OF RESULTS
The mean of the two results shall be reported to the nearest whole number as the aggregate impact
value of the tested material. Aggregate impact value is used to classify the stones in respect of their
toughness property as indicated below in Table 1.

Table1: Classification of aggregate based on aggregate impact value

Aggregate impact value (%) Quality of aggregate

<10 Exceptionally strong

10–20 Strong

Satisfactory for road surfacing

20–30

>35 Weak for road surfacing

Table 2: Maximum allowable impact values of aggregate in different types of Pavement

Material / layers
Sl.No Types of pavement material/layer Aggregate impact value (%)

1 Water bound macadam, sub-base course 50

2 Cement concrete, base course 45

3 i) WBM base coarse with bitumen surfacing

ii) Built-up spray grout, base course 40

4 Bituminous macadam, base course 35

5 i) WBM, surfacing course

ii) Built-up spray grout, surfacing course
iii) Bituminous penetration macadam
iv) Bituminous surface dressing
v) Bituminous macadam, binder course 30
vi) Bituminous carpet
vii) Bituminous/Asphaltic concrete
viii) Cement concrete, surface course
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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7. CONCLUSION

Record of Observation Sample I Sample II

Total weight of dry sample taken = W1 gm
Weight of portion passing 2.36 mm sieve = W2 gm
Aggregate impact = (W2/W1)*100
Value (per cent)

Aggregate Impact Mean Value =

QUESTIONS: / VIVA VOCE-

1. How aggregate impact value is expressed?
2. How does toughness differ from compressive strength?
3. Aggregate impact value material A is 20 and that of B is 45. Which one is better surface course and
why?
4. Which test simulates the field conditions better, aggregate crushing value test or impact value test?
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Experiment No. 2

Test on aggregate: Specific gravity test

AIM: To determine the specific gravity of a given aggregate sample.

THEORY: Specific gravity is defined as the ratio of the weight of a given volume of aggregate to the
weight of an equal volume of water. It is a measure of the density of the aggregate compared to the
density of water. Specific gravity is an important property of aggregates used in construction, as it
provides information about the quality and strength of the material. The specific gravity test on aggregate
is found as per I.S.-2386 part III.

APPARATUS:

a) Balance, sensitive to 0.01 g

b) Pycnometer
c) Funnel
d) Graduated jar
e) Water tank
f) Tray
g) Cloth for drying the sample

PROCEDURE:

1. Take a clean, dry pycnometer and determine its weight (W1).

2. Fill the pycnometer about one-third full with the dry aggregate sample.
3. Weigh the pycnometer with the aggregate (W2).
4. Fill the pycnometer with water up to the calibration mark, ensuring no air bubbles are present.
5. Weigh the pycnometer with the aggregate and water (W3).
6. Empty the pycnometer and fill it completely with water up to the calibration mark. Weigh it (W4).
7. Calculate the specific gravity using the formula.
OBSERVATIONS AND CALCULATION:

Description Weight (g) Description Weight (g)

Weight of pycnometer (W1)

Weight of pycnometer + aggregate (W2)

Weight of pycnometer + aggregate + water (W3)

Weight of pycnometer + water (W4)

(W 2−W 1)
Specific Gravity =
( W 2−W 1 )−(W 3−W 4)

RESULTS:
The specific gravity of the given aggregate sample is ________.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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QUESTIONS:
1. Why is specific gravity an important property for aggregates in construction?
2. How does the presence of air bubbles affect the specific gravity test?
3. What is the significance of using a specific gravity bottle in this test?
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Experiment No. 3
SHAPE TEST
A. FLAKINESS INDEX
1. OBJECTIVE
This method of test lays down the procedure for determining the flakiness index of the coarse
aggregate.
2. PRINCIPLE
The flakiness index of an aggregate is the percentage by weight of particles in it whose least dimension
(thickness) is less than three-fifths of their mean dimension. The test is not applicable to sizes smaller
than 6.3mm.
3. APPARATUS
The apparatus shall consist of the following:
1) A balance – The balance shall be of sufficient capacity and sensitivity and shall have an accuracy of
0.1 percent of the weight of the test sample
2) Metal Gauge – The metal gauge shall be of the pattern as shown in Fig 4
3) Sieves – The sieves of sizes as shown in Table 1 & 2.
4. PROCEDURE
1) A quantity of aggregate shall be taken sufficient to provide the minimum number of 200 pieces of
any fraction to be tested.
2) The sample shall be sieved with sieves specified in Table 6.
3) Then each fraction shall be gauged in turn for thickness on a metal gauge of the pattern shown in Fig
4 or in bulk on sieves having elongated slots. The width of the slot used in the gauge or sieve shall be
of the dimensions specified in column 3 of Table 6 for the appropriate size of material.
4) The total amount of aggregate passing the gauge shall be weighed to an accuracy of at least 0.1
percent of the weight of the test sample
Table1. Flakiness Index
SIZE OF AGGREGATE WEIGHT OF WEIGHT OF FLAKINESS
(mm) THICKNESS AGGREGATE AGGREGATE INDEX OF
Passing GAUGE(mm) OF THIS SIZE FRACTION EACH
GROUP (GM) PASSING FRACTION OF
through Retained on THROUGH THE AGGREGATE
IS (0.6 TIMES SLOT (GM) (%)
IS sieve THE MEAN
sieve SIEVE SIZE)
mm
63 50 33.90
50 40 27.00
40 31.5 19.50
31.5 25 16.95
25 20 13.50
20 16 10.80
16 12.5 8.55
12.5 10 6.75
10 6.3 4.89
FI = (W2/W1) * 100 W1= W2= FI= %
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Fig4.THICKNESS GAUGE

5. CALCULATION
Flakiness index % (x) = (W2/W1)* 100 %

6. REPORTING OF RESULTS
The flakiness index is the total weight of the material passing the various thickness gauges, expressed
as the percentage of the total weight of the sample gauged.

7. CONCLUSION
Flakiness index =

B. ELONGATION INDEX

1. OBJECTIVE
This method of test lays down the procedure for determining the elongation index of the coarse
aggregate.

2. PRINCIPLE
The elongation index of an aggregate is the percentage by weight of particles in it whose greatest
dimension (thickness) is greater than one and four-fifths of their mean dimension. The test is not
applicable to sizes smaller than 6.3mm.

3. APPARATUS
The apparatus shall consist of the following:
4) A balance – The balance shall be of sufficient capacity and sensitivity and shall have an accuracy of
0.1 percent of the weight of the test sample
5) Metal Gauge – The metal gauge shall be of the pattern as shown in Fig 5
6) Sieves – The sieves of sizes as shown in Table 1 & 2.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
ENGG., VARANASI

4. PROCEDURE
5) A quantity of aggregate shall be taken sufficient to provide the minimum number of 200 pieces of
any fraction to be tested.
6) The sample shall be sieved with sieves specified in Table 6.
7) Each fraction shall be gauged in turn for length on a metal gauge of the pattern shown in Fig 5. The
gauge length used shall be of the dimensions specified in column 4 of Table 6 for the appropriate size
of material.
8) The total amount of aggregate retained by the length gauge shall be weighed to an accuracy of at
least 0.1 percent of the weight of the test sample

Fig. 5: Length gauge

Table 2. Elongation Index

SIZE OF AGGREGATE WEIGHT OF WEIGHT OF ELONGATIO

(mm) LENGTH AGGREGAT AGGREGAT N INDEX OF
Passing GAUGE(mm) E OF THIS E FRACTION EACH
through Retained on SIZE GROUP RETAINED FRACTION
IS (1.80 TIMES (GM) ON THE OF
IS sieve THE MEAN GAUGE AGGREGATE
sieve SIEVE SIZE) (GM) (%)
mm
63 50 -
50 40 81.0
40 31.5 58.5
31.5 25 -
25 20 40.5
20 16 32.4
16 12.5 25.6
12.5 10 20.2
10 6.3 14.7
EI=(W4/W3) * 100 W3 W4 EI= %

5. CALCULATION
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Elongation index % (y) =(W4/W3)* 100 %

Combined flakiness and elongation index (%) = x + y =

Questions
1. What is the significance of shape of aggregate in pavement construction?

2. Discuss the effects of flaky and elongated aggregate in road construction.

3. Discuss the advantages and limitations of rounded and angular aggregates in different types of
pavements.
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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ExperimentNo.4
DETERMINATION OF LOS ANGELES ABRASION VALUE
1. OBJECTIVE

1) To determine Los Angeles abrasion value.

2) To find out the suitability of aggregates for its use in road construction.

2. PRINCIPLE

The aggregates used in surface course of the highway pavements are subjected to wearing due to
movement of traffic. When vehicles move on the road, the soil particles present between the
pneumatic tyres and road surface causes abrasion of road aggregates. The steel reamed wheels of
animal driven vehicles also cause considerable abrasion of the road surface. Therefore, the road
aggregate should be hard enough to resist the abrasion. Resistance to abrasion of aggregates is
determined in laboratory by Los Angeles test machine.

The principle of Los Angeles abrasion test is to produce the abrasive action by use of standard
steel balls which when mixed with the aggregates and rotated in a drum for specific number of
revolutions also causes impact on aggregates. The percentage wear of the aggregates due to
rubbing with steel balls is determined and is known as Los Angeles Abrasion Value.

3. APPARATUS

The apparatus as per IS:2386 (Part IV)–1963consists of:

1) Los Angeles Machine: It consists of a hollow steel cylinder, closed at both the ends
with an internal diameter of 700 mm and length 500 mm and capable of rotating about its
horizontal axis. A removable steel shaft projecting radially 88 mm into cylinder and
extending full length (i.e. 500 mm) is mounted firmly on the interior of cylinder. The shelf
is placed at a distance 1250 mm minimum from the opening in the direction of rotation.
2) Abrasive charge: Cast iron or steel balls, approximately 48 mm in diameter and
each weighing between 390 to 445 g; 6 to 12 balls are required.
3) Sieve: The 1.70mm IS sieve
4) Balance of capacity 5 kg or 10 kg
5) Drying oven
6) Miscellaneous like tray etc
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Fig3 LOS ANGELES ABRASION TESTING MACHINE

4. PROCEDURE
Test Sample: It consists of clean aggregates dried in oven at 105 - 110oC and coarser than 1.70
mm sieve size. The sample should conform to any of the grading shown in table.

Table 3 Grading of Test Samples

Sieve
size Weighting of Test Sample for Grade
(square hole)

Passing Retained A B C D E F G
mm on mm

80 63 - - - - 2500* - -

63 50 - - - - 2500* - -
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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50 40 - - - - 5000* 5000* -

40 25 1250 - - - - 5000* 5000*

25 20 1250 - - - - - 5000*

20 12.5 1250 2500 - - - - -

12.5 10 1250 2500 - - - - -

10 6.3 - - 2500 - - - -

6.3 4.75 - - 2500 - - - -

4.75 2.36 - - 5000 - - -

*Tolerance of ±12 percent permitted.

1) Select the grading to be used in the test. It should be chosen such that it
conforms to the grading to be used in construction, to the maximum extent possible.
2) Take 5kg of sample for grading A, B, C or D and 10kg for grading E, F and G.
3) Choose the abrasive charge as per Table 2.

Table-4 Selection of Abrasive Charges

Grading No. of Steel balls Weight of charge , gm

A 12 5000±25
B 11 4584±25
C 8 3330±25
D 6 2500±25
E 12 5000±25
F 12 5000±25

The test sample and the abrasive charge shall be placed in the Los Angles abrasion testing
machine.
1) The machine is rotated at a speed of 20 to 33 rev/min for grading A, B,C and D, the machine
shall be rotated for 500 revolutions; for grading E, F and G, it shall be rotated for 1000
revolutions
2) The material is discharged from the machine after the completion of the test and is sieved
through 1.7 mm IS sieve.
3) The weight of the aggregate passing through 1.7mm sieve is taken and recorded

5. REPORTING OF RESULTS

The difference between the original weight and the final weight of the test sample shall be expressed
as a percentage of the original weight of the test sample. This value is reported as the percentage wear.

Table 5 Maximum L A Abrasion values of aggregates in different types of pavement layers

BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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Maximum Los
Value (%)

Sl. no. Types of pavement layer

1 Water bound macadam, sub-base course 60

2 i) WBM base course with bituminous surfacing
ii) Bituminous macadam base course 50

iii) Built-up spray grout base course

3 i) WBM surfacing course
ii) Bituminous macadam binder course 40
iii) Bituminous penetration macadam

iv) Built-up spray grout binder course

4 i) Bituminous carpet surface course
ii) Bituminous surface dressing, single or two coats 35
iii) Bituminous surface dressing, using pre-coated
aggregates
5 i) Bituminous concrete surface course

ii) Cement concrete pavement surface course 30

6. CONCLUSION
Los Angeles Abrasion value =
Sample I Sample II

Total weight of dry sample taken= W1gm

Weight of portion passing 1.7 mm sieve=

W2gm

Aggregate abrasion value

= (W2/W1)*100 Value (per cent)

Mean Los Angeles Abrasion value =

QUESTIONS:
1. How does impact occur in Los Angeles abrasion test?
BCE-651(TRANSPORTATION ENGG. LAB) DEPTT. OF CIVIL ENGG., SHEAT - COLLEGE OF
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2. How is Los Angeles abrasion value expressed?
3. Sample A and B have Los Angeles abrasion value is 15 and 30 respectively which sample is
harder?