1. AGGREGATES

2. Sieve Analysis Test

3. Sieve Analysis Test • To determine gradation (size distribution) of
aggregates.
Standard Sieves Are :
80mm,40mm,20mm,10mm,4.75mm,2.36mm,1.18m m,600 microns, 300 microns, 150 microns, 75 microns

6. Aggregate Gradation IS:2386-1963 Part I
The gradation and size test (Figure 1) is used to determine aggregate particle size distribution

7. In a gradation and size analysis, a sample of dry aggregate of known weight is separated through a series of sieves with progressively smaller openings.
Once separated, the weight of particles retained on each sieve is measured and compared to the total sample weight.
Particle size distribution is then expressed as a percent retained by weight on each sieve size.

8. Sieves and Sieve Shaker for Coarse Aggregate

9. Sieve Shaker for Fine Aggregate

10. FM= 277/100=2.77

14. STONE AGGREGATE Desirable Properties 1.Strength 2.Hardness 3.Toughness
4.Durability
5.Shape
6.Adhesion with Bitumen

16. AGGREGATE CRUSHING VALUE TEST
Cylinder
Machine steel, 154 mm dia.
Plunger
Machine steel
Base Plate
Metal Measure
115 mm dia., 180 mm deep.
Tamping Rod
Galvanized steel, 16 mm dia., 500 mm length, hemispherical at both ends.

18. TEST PROCEDURE Sample Preparation Load Application 40 KN/min
Total Load 400 KN.
Crushed Material is Passed through 2.30mm sieve
CALCULATIONS AND RESULTS
Mass of test specimen = M1 g
Mass of material passing 2.36 mm sieve = M2 g
Aggregate Crushing Value (ACV) = 100 xM2 M1
Report the average ACV

20. IRC Specifications For Surface Courses : Not more than 30%
For Base Courses : Not More than 45%

21. AGGREGATE IMPACT TEST Used to determine the Toughness Apparatus:
Impact Machine
Cylindrical Measure
Machine steel, 75 mm dia., 50 mm deep.
Tamping Rod
Galvanized steel, 3/8" dia., 8" length
Sieves of Size 12.5mm, 10mm , 2.36

23. Test Procedure Sample Preparation Place the Cup into the machine
Apply 15 blows by lifting the hammer of 13.5 kg to 14 kg to a height of 38 cm.
Remove the material from cup and sieve it through 2.36 mm sieve.
Impact Value = M2 x100 M1
Where M2= weight of Crushed material in gm
M1 = weight of Sample taken

25. IRC Specifications For Surface Courses : Not more than 30%
For Bituminous
Macadam Courses : Not More than 35%
For WBM courses : not more than 40%

26. ABRASION TESTS Used to Evaluate the Hardness Property of Aggregate.
Los Angels Abrasion Test
Deval’s Abrasion Test
Deval’s Attrition Test

27. Los Angels Abrasion Test
Hollow Drum
12.5mm thick steel plate;
70cm inner diameter 50cm inner
width
Drum Speed
30-33 RPM
IS sieves of specified sizes
Abrasive charge shall consist of a solid, steel sphere having a mass
between 390 and 445 g. with a diameter of 46.5 ± 0.5 mm.

28. GRADINGS FOR TEST SPECIMENS
A, B, C, D, E, F and G
Total Mass = 5000 ± 10 gm for A, B, C and D
Total Mass = 10,000 ± 20 gm for E, F and G.

29. TEST PROCEDURE Take the sample as per specifications
Place it in the drum
Also place the abrasive charge as per Sp.
Apply the Rotations r.p.m.
1000 revolutions are to be given
Remove the shutter and sample is passed through the 1.70mm sieve.
Abrasion Value = W2 x100 W1
Where W2= weight of abraded material retained
W1 = weight of Sample taken

33. IRC Specifications For CC Roads&High Bituminous Roads :
Not more than 30%
For WBM courses : not more than 50%

34. DEVAL’S ABRASION TEST

35. FLAKINESS INDEX TEST ELONGATION INDEX TEST ANGULARITY NUMBER TEST
SHAPE TESTS
FLAKINESS INDEX TEST
ELONGATION INDEX TEST
ANGULARITY NUMBER TEST

36. The particle shape of aggregates is determined by the percentages of flaky and elongated particles.
Flaky and elongated particles are considered undesirable as they cause weakness of the pavement.
Rounded aggregates are preferred in cement concrete pavements as the workability of concrete improves.
A regular shape of particles are desirable for granular base course due to increased stability desired from better interlocking.

37. FLAKINESS INDEX TEST Definition:
Aggregate particles are classified as flaky when they have a thickness (smallest dimension) of less than 0.6 of their mean sieve size.
The flakiness index of an aggregate sample is found by
separating the flaky particles and expressing their mass as a percentage of the mass of the sample tested. This test is not applicable to aggregate passing 6.30 mm sieve and retained as 63.0 mm sieve.

38. 7.3.1 Apparatus
Metal thickness gauge
Test sieves, balance, trays

39. 1 This dimension is equal to 0.6 times the mean test sieve size.

40. Procedure
The sieve sample with sieves mentioned in Table 7.1. Weigh each of the individual size fractions (w1, w2, w3, ...) retained on these sieves, other than the 63.0 mm sieve and store them in separate trays marked with their size.
2. Gauge each fraction from the respective slots in the thickness gauge weigh pieces which pass through the slots (x1, x2, x3, …. etc.).

41. Calculations and Results
Flakiness index =
Where
x1, x2, ... etc. are the weight of the fractions passing from the thickness gauge.
w1, w2,…, etc. are the weight of the original sample retained as the corresponding sieves.

42. IRC SPECIFICATIONS Normally should not exceed 15%
In any case it should not exceed 25%

43. ELONGATION INDEX TEST Definition:
Aggregate particles are classified as elongated when they have a length (greatest dimension) of
more than 1.8 of their mean sieve size.
The elongation index is found by separating the
elongated particles and expressing their mass as a percentage of the mass of sample tested.
The test is not applicable to material passing mm sieve or retained on 50 mm sieve.

44. Apparatus
Metal Length gauge
Test sieves, balance, trays

45. 2 This dimension is equal to 1.8 times the mean test sieve size.

46. PROCEDURE
1. Sieve the sample with sieves mentioned in Table (7.2) weight each of the individual size fractions (w1, w2, w3, … etc.) retained on these sieves other than the 50.0 mm sieve.
2. Gauge each fraction as follows, select the length gauge appropriate to the single fraction under test and gauge each particle separately by hand.
Elongated particles are those whose greatest dimension prevents them from passing through the gauge.
3.Weigh each fraction which doesn’t pass through the gauge (y1, y2, …etc.).

47. Calculations and Results
Elongation index =
Where y1, y2, ... etc. are the weight of the fractions passing from the thickness gauge.
w1, w2,…, etc. are the weight of the original sample retained as the corresponding sieves.

49. IRC SPECIFICATIONS
In any case it should not exceed 15%

50. Angularity number
Angular particles possess well defined edges and are commonly found in aggregates prepared by crushing of rocks.
Angularity or absence of rounding of particles in aggregate is a property which is of importance because it affects ease of handling a mixture of aggregate and binder.
The degree of packing of particles of single sized aggregates depends upon the shape and angularity of the aggregate.

51. Angularity of aggregate can be estimated from properties of voids in a sample of aggregate compacted in a particular manner.
Rounded gravel particles possess lesser voids (mostly 33%, i.e. 67% solids, by volume) as compared to the angular particles.
Angularity number measures the percentage of voids in angular particles in excess of that in the rounded gravel particles.

52. Angularity number
= % of solid volume in a vessel filled with aggregate in a standard manner - 67 (i.e. % volume of solids of the rounded gravel)
The higher the angularity number, the more angular the aggregate.
The range of angularity number for practical aggregates is between 0 and 11

53. Unit Weight
(unit mass or bulk density)
The weight of the aggregate required to fill a container of a specified unit volume.
• Volume is occupied by both the aggregates and the voids between the
aggregate particles.
• Depends on size distribution and
shape of particles and how densely the
aggregate is packed
• Loose bulk density
• Rodded or compact bulk density