GCE Kannur

1. Exp.No.1
GRAIN SIZE ANALYSIS
1. Aim
To determine the particle size distribution of coarse aggregate by sieving or screening.
2. Principle
Grain size analysis expresses quantitatively the percentage, by weight of various sizes of
particles present in the aggregate sample. This analysis is used for classification of aggregate
based on grain size. The determination of particle size distribution is very important in road mix
design purpose.
3. Apparatus
1.Sieves 80.0,63.0,50.0,40.0,31.5,25.0,20.0,16.0,12.5,10.0,6.3,4.75,3.35,2.36,1.18,0.6,
0.3,0.15 and 0.075 mm
2.Balance – the balance or scale shall be such that it is readable and accurate to 0.1
percent of the weight of the test sample.
4. Procedure
1.The sample shall be brought to an air dry condition before weighing and sieving. This
may be achieved either by drying at room temperature or by heating at a temperature of 100 to
110o
C. The air dry sample shall be weighed and sieved successively on the appropriate sieves
starting with the largest. Care shall be taken to ensure that the sieves are clean before use.
2.Each sieve shall be shaken separately over a clean tray until not more than a trace
passes, but in any case for a period of not less than two minutes. The shaking shall be done with
a varied motion, backwards and forwards, and forwards left to right, circular clockwise and anti-
clockwise, and with frequent jarring, so that the material is kept moving over the sieve surface
in frequently changing directions. Material shall not be forced through the sieve by hand
pressure, but on sieves coarser than 20-mm, placing of particles is permitted. Lumps of fine
material, if present, may be broken by gentle pressure with fingers against the side of the sieve.
Light brushing with a soft brush under the side of the sieve may be used to clear the sieve
opening.
3. Light brushing with a fine camel hair brush may be used on the 150-micron and 75
micron IS sieves to prevent aggregating of powder and blinding of apertures. Stiff or worn out
brushes shall not be used for this purpose and pressure shall not be applied to the surface of the

2. sieve to force the particle through the mesh. On completion of sieving, the material retained on
each sieve, together with any material cleaned from the mesh, shall be weighed.
4. In order to prevent blinding of the sieve apertures by over-loading, the amount of
aggregate placed on each sieve at completion of the operation is not greater than the value given
for that sieve in table 3 .Sample weights given in table 4 will thus normally require several
operations on each sieve.
Table 3. Maximum weight to be retained at the completion of sieving
Coarse aggregate Fine aggregate
IS Sieve Maximum weight for
(kg )
IS Sieve Maximum weight
for ( g)
45 cm dia sieve 30 cm dia
sieve
20-cm dia Sieve
50 mm 10 4.5 2.36 mm 200
40 mm 8 3.5 1.18mm 100
31.5mm or25 mm 6 2.5 0.6 mm 75
20 mm 4 2 0.3 mm 50
16 mmor12.5 mm 3 1.5 0.15mm 40
10 mm 2 1 0.075mm 25
6.3 mm 1.5 0.75
4.75 mm 1 0.5
3.35 mm - 0.3
Table IV Minimum weight of sample for sieve analysis
Maximum size present in substantial
proportions
Minimum weight of sample to be taken for
sieving
In mm In kg
63 50
50 35
40 or31.5 15
25 5
20 or 16 2
12.5 1
10 0.5
6.3 0.2
4.75 0.2
2.36 0.1
5. Result

3. Record of Observation
Sieve size in
(mm)
Weight retained
in(g)
% weight retained Cumulative %
retained
% finer
Calculations

4. Exp.No.2
SHAPE TEST
1. Aim
To determine the flakiness and elongation index of the given aggregates
2. Principle
The particle shape of aggregates is determined by the percentages of flaky and elongated
particles contained in it. For base course and construction of bituminous and cement concrete
types, the presence of flaky and elongated particles are considered undesirable as they may cause
inherent weakness with possibilities of breaking down under heavy loads. thus evaluation of
shape of the particles, particularly with reference to flakiness and elongation is necessary.
The flakiness Index of aggregates is the percentage by weight of particles whose least
dimension(thickness) is less than three-fifths(0.6 times) of their mean dimension. This test is not
applicable to sizes smaller than 6.3 mm.
The Elongation Index of an aggregate is the percentage by weight of particles whose
greatest dimension(length) is greater than four-fifths (0.8 times) their mean dimension,. The
elongation test is not applicable for sizes smaller than 6.3 mm.
3. Apparatus
1. A standard thickness gauge
2. A standard length gauge
3. IS sieves of sizes 63,50,40,31.5,25,20,16,12.5,10 and 6.3 mm.
4. A balance of capacity 5 kg, readable and accurate up to 1 gm.
4. Procedure
1. Sieve the sample through the IS sieves ( as specified in the table).
2. Take a minimum of 200 pieces of each fraction to be tested and weigh them.
3. In order to separate the flaky materials, gauge each fraction for thickness on a
thickness gauge. The width of the slot used should be of the dimensions specified in column (3)
of the table for the appropriate size of the material.
4. Weigh the flaky material passing the gauge to an accuracy of at least 0.1 per cent of the
test sample.

5. 5. In order to separate the elongated materials, gauge each fraction on the length gauge.
Weigh the elongated material retained on the gauge to an accuracy of at least 0.1 per cent of the
test sample.
5. Result
1. Flakiness Index =
2. Elongation Index =

6. Record of Observation
Size of aggregates Weight of
the fraction
consisting of
at least 200
pieces, g
Thickness
gauge size,
mm
Weight of
Aggregates
in each
fraction
passing
thickness
gauge, g
Length
gauge size,
mm
Weight of
aggregates
in each
fraction
retained on
length
gauge, g
Passing
Through IS
Sieve, mm
Retained on
IS Sieve,
mm
1 2 3 4 5 6 7
63 50 W1= w1= -
50 40 W2= w2= x1=
40 31.5 W3= w3= x2=
31.5 25 W4= w4= -
25 20 W5= w5= x3=
20 16 W6= w6= x4=
16 12.5 W7= w7= x5=
12.5 10 W8= w8= x6=
10 6.3 W9= w9= x7=
Total W= w= x=
Calculations
1. Flakiness Index = (w1+w2+w3+.............) x100
(W1+W2+W3+..........)
2. Elongation Index = (w1+w2+w3+.............) x100
(W1+W2+W3+..........)

7. Exp.No.3
ANGULARITY NUMBER
1. Aim
To determine the angularity number of coarse aggregate.
2. Principle
Based on the shape of the aggregate particle, stones may be classified as rounded, angular
and flaky. Angular particles possess well defined edges formed at the intersection of roughly
plane faces and are commonly found in aggregates prepared by crushing of rocks. Since weaker
aggregates may be crushed during compaction, the angularity number does not apply to any
aggregate which breaks down during compaction. Angularity or absence of the rounding of the
particles of an aggregate is a property which is of importance because it affects the ease of
handling a mixture of aggregate and binder or the workability of the mix. The determination of
angularity number of an aggregate is essentially a laboratory method intended for comparing the
properties of different aggregates for mix design purposes and for deciding their gradation
requirements. The degree of packing of particles of single sized aggregate depends on the shape
and angularity of aggregates. If a number of single size spherical particles are packed together in
the densest form, the total volume of solids will be 67 per cent and the volume of voids 33
percent of the total volume. However if the shape of the particles of the same size deviates from
the spherical shape to irregular or angular shape.When they are densely packed the volume of
solids decreases resulting in an increase in the volume of voids. Hence the angularity of the
aggregate can be estimated from the properties of voids in a sample of aggregates compacted in a
particular manner. The angularity number of an aggregate is the amount by which the
percentage voids exceeds 33 after being compacted in a prescribed manner. The angularity
number is found from the expression. (67 minus the percent solid volume). Here the value 67
represents the percentage volume of solids of most rounded gravel which would have 33 percent
voids.
3. Apparatus
1. A metal cylinder closed at one end and of about 3 litre capacity diameter and
height of this being approximately equal, i.e. about 15.64 cm diameter x 15.64
cm height.
2. A metal tamping rod of circular cross-section, 16 mm in diameter and 60 cm in
length, rounded at one end.
3. A metal scoop of about 1 litre Heaped capacity of size 20 x 10 x 5 cm, and

8. A balance of capacity 10 kg to weigh up to 1 g.
4. Procedure
1. Calibrate the cylinder by determining the weight of water at 270
C required to fill it so
that no meniscus is present above the rim of the container. The amount of aggregate available
should be sufficient to provide, after separation on the appropriate pair of sieves, at least 10 kg
of the predominant size as determined by sieve analysis on the 20, 16, 12.5,10, 6.3 and 4.75 mm
IS sieves.
2. Test sample : The amount of aggregate available should be sufficient to provide, after
separation on the appropriate pair of sieves, at least 10kg of predominant size, as determined by
sieve analysis on the aggregate retained between the appropriate pair of IS sieves from the
following sets: 20 and 16 mm, 16 and 12.5mm, 12.5 and 10 mm, 10and 6.3, 6.3and 4.75 mm.
Note: In case of aggregate larger than 20 mm sieve is used, the volume of the cylinder should be
greater than 3 litres. But when the aggregates smaller than 4.75mm size are used, a smaller
cylinder may be used, the procedure of the test is the same for each of these except that the
amount of compactive effort given by (weight of tamping rod x height of fall x number of blows)
should be proportional to the volume of the cylinder.
3. Select the sample of single-size retained between the specified pair of sieves. Then dry
it in an oven at a temperature of 100 to 110o
C for 24 hours and cool it in an air tight container.
4. Fill the scoop and heap it to overflowing with the aggregate. Place the aggregate in the
cylinder by allowing it to slide gently off the scoop from the lowest possible height.
5. Compact the aggregate in the cylinder by 100 blows of the tamping rod at the rate of
about 2 blows per second. Apply each blow by holding the rod vertically; with its rounded end 5
cm above the surface of aggregate and releasing it so that it falls vertically and no force is
applied on it. The blows should be distributed evenly over the surface.
6. Repeat the process of filling and tamping with a second and the third layer of
aggregates. The third layer should contain only the aggregate required to just fill up the cylinder
level before tamping. After the third layer is tamped, fill the cylinder to overflowing, and strike
the aggregates off level with the top using the tamping rod as the straight edge.
7. Add individual pieces of aggregate and roll in to the surface by rolling the tamping rod
across the upper edge of the cylinder, until the aggregates do not lift the rod off the edge. No
downward pressure should be applied on the rod.
8. Weigh the aggregate with the cylinder to the nearest 5g. Make separate
determinations and calculate the mean weight of the aggregate. If the result of any one

9. determination differs from the mean by more than 25 g, make three additional determinations
and find the mean of all the six determinations.
Then Angularity number = 67-100 W/CG
Where W = mean weight of the aggregates in the cylinder, g
C = weight of water required to fill in the cylinder, g
G = specific gravity of aggregate
5.Result
Angularity number =

10. Record of Observations
Weight of water filling the cylinder = C g =
Specific gravity of the aggregate = G =
Particulars Trial number
1 2 3 Mean 4 5 6 Mean
Weight of
aggregate
filling the
cylinder to the
nearest 5 g
Mean weight of the aggregates filling the cylinder, W g =
Calculations
Angularity Number = 67-100W/CG

11. Exp.No.6
DETERMINATION OF LOS ANGELES ABRASION VALUE
1. Aim
To determine the Los Angeles abrasion value of aggregate
2. Principle
The aggregate 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 aggregates should be hard enough to resist the abrasion. Resistance to
abrasion of aggregate 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 specified
number of revolutions also cause 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)-1963 consists 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; six to twelve balls are required.
3. Sieve: The 1.70 mm IS Sieve.
4. Balance of capacity 5 kg or 10 kg
5. Drying oven
6. Miscellaneous like tray etc.

12. 4. Procedure
Test sample: It consists of clean aggregates dried in oven at 105-110o
C and are coarser
than 1.7mm sieve size. The sample should conform to any of the grading shown in Table 1
below
Table 1.
Sieve size Weight in g of test sample for grade
Passing
In mm
Retained
on in mm
A B C D E F G
80 63 - - - - 2500 - -
63 50 - - - - 2500 - -
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 - - -
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 5 kg of sample for grading A, B, C or D and 10 kg for grading, E, F and G.
3. Choose the abrasive charge as per Table 2
Table 2
Grading No. of steel balls Weight of charge, g
A 12 5000±25
B 11 4584±25
C 8 3330±20
D 6 2500±15
E 12 5000±25
F 12 5000±25
G 12 5000±25

13. 4. The test sample and the abrasive charge shall be placed in the Los Angeles abrasion
machine and a machine rotated at a speed of 20 to 33 rev/min.
5. For grading A,B,C and D the machine shall be rotated for 500 revolutions: for grading
E,F,G it shall be rotated for 500 revolutions
6. The machine shall be so driven and so counter-balanced as to maintain a substantially
uniform peripheral speed. If an angle is used as the shelf, the machine shall be rotated in such a
direction that the charge is caught on the outside surface of the angle. At the completion of the
test, the material shall be discharged from the machine and preliminary separate the sample made
on a sieve coarser than the 1.7mm IS Sieve.
7. The material coarser than the 1.7mm IS Sieve shall be washed dried in an oven at 105
to 110o
C to a substantially constant weight, and accurately weighed to the nearest gram.
Los Angeles abrasion value= (A/B)*100
Where,
A = difference between the original weight and the final weight of the test sample
B = Total weight of the sample taken
5. Result
The Los Angeles abrasion value of given sample is =

14. Record of observation
Los Angeles abrasion value= (A/B)*100
Where,
A ( difference between the original weight
and the final weight of the test sample) =
B (Total weight of the sample taken ) =
Calculations