A sieve analysis (or gradation test) is a practice or procedure used to assess the particle size distribution (also called gradation) of a granular material by allowing the material to pass through a series of sieves of progressively smaller mesh size and weighing the amount of material that is stopped by each sieve as a fraction of the whole mass.
Sieve analysis helps to determine the particle size distribution of the coarse and fine aggregates.This is done by sieving the aggregates as per IS: 2386 (Part I) – 1963.
This method covers the procedure for the determination of particle size distribution of fine, coarse and all-in-aggregates by sieving or screening.
Apparatus
- Sieves: Sieves of the sizes given in Table-I, conforming to IS : 460-1962 Specification for Test Sieves (Revised) shall be used.
- 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.
Table-I (Specification for Test Sieves)
IS:460-1962...
| Sr. |
Type |
Sieve Designations |
| 1. |
Square hole, perforated plate |
80-mm, 63-mm, 50-mm, 40-mm, 31.5-mm, 25-mm, 20-mm, 16-mm, 12.5-mm, 10-mm, 6.3-mm, 4.75-mm |
| 2. |
Fine mesh, wire cloth |
3.35-mm, 2.36-mm, l.l8-mm, 600-μm, 300-μm, 150-μm, 75-μm |
Preparation of Sample
- The weight of sample available shall be not less than the weight given in Table-II. The sample for sieving (see Table-II) shall be prepared from the larger sample either by quartering or by means of
a sample divider.
Table-II (Minimum Weight for Sampling)
Sample for sieving...
| Sr. |
Maximum Size Present in Substantial Proportions (mm) |
Minimum weight of Sample Despatched for Testing (kg) |
| 1. |
63 |
100 |
| 2. |
50 |
100 |
| 3. |
40 |
50 |
| 4. |
25 |
50 |
| 5. |
20 |
25 |
| 6. |
16 |
25 |
| 7. |
12.5 |
12 |
| 8. |
10 |
6 |
| 9. |
6.3 |
3 |
Test Procedure for Coarse and Fine Aggregate
- 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 110°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.
- 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, 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 on the under side of the sieve may be used to clear the sieve openings.
- Light brushing with a fine camel hair brush may be used on the 150-micron and 75-micron IS Sieves to prevent aggregation 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 sieve to force particles through the mesh.
On completion of sieving, the material retained on each sieve, together with any material cleaned from the mesh, shall be weighed.
- In order to prevent binding of the sieve apertures by overloading, the amount of aggregate placed on each sieve shall be such that the weight of the aggregate retained on the sieve at completion of the operation is not greater than the value given for that sieve in Table-III.
Sample weights given in Table-IV will thus normally require several operations on each sieve.
Note-1:
For many routine purposes mechanical sieving is advantageous, but if this method is used, care should taken to ensure that the sieving is complete.
Note-2:
The following alternative procedure is permissible where it is required to determine only the cumulative percentage figures:
The weighted sample shall be passed through the largest of the appropriate sieves as described above. The fraction which passed the sieve shall be weighted as then passed through next smaller sieves the fraction which passes shall be weighted, and so on.
The cumulative weight passing each sieve shall be calculated as percentage of the total sample weight.
Note-3:
If sieving is carried out with a nest of sieves on machine, not less than 10 minutes sieving will be required for each test.
Test Procedure for All-in-Aggregates or Mixed Coarse and Fine Aggregates
- The weight of sample available shall not be less than the weight given in Table II. The sample for sieving (see Table-IV ) shall be prepared from the larger sample either by quartering or by means of a sample divider.
It shall be brought to 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°C to 110°C.
- In some cases the sieve analysis of all-in-aggregate can be carried out in accordance with the procedure given in 2.4.
Frequently, however, this will result in heavy overloading of the finer sieves.
In such cases it will be necessary to make a preliminary separation of the all-in-aggregate
into two fractions, coarse and fine, using for this purpose a convenient sieve for example, a 3.35-mm or 4.75-mm IS Sieve.
- If the amount of either the coarse or fine aggregate obtained as above is substantially less than that required for testing in accordance
with Table-IV, another sample shall be taken which is sufficiently large to produce an adequate sample of both the coarse and the fine aggregate.
If the amount of either the coarse or the fine aggregate thus obtained is substantially greater than that required for testing, it shall be reduced by
quartering or by means of a sample divider.
Table-III (Maximum weight to be retained at the completion of Sieving)
Clause 2.4.4...
| Sr. |
Coarse Aggregate |
Fine Aggregate |
| IS Sieve |
Maximum Weight for
45-cm diameter Sieve (kg) |
Maximum Weight for
30-cm diameter Sieve (kg) |
IS Sieve |
Maximum Weight for
20-cm diameter Sieve (g) |
| 1. |
50-mm |
10 |
4.5 |
2.36-mm |
200 |
| 2. |
40-mm |
8 |
3.5 |
1.18-mm |
100 |
| 3. |
31.5-mm OR 25-mm |
6 |
2.5 |
600-μm |
75 |
| 4. |
20-mm |
4 |
2.0 |
300-μm |
50 |
| 5. |
16-mm OR 12.5-mm |
3 |
1.5 |
150-μm |
40 |
| 6. |
10-mm |
2 |
1.0 |
75-μm |
25 |
| 7. |
6.3-mm |
1.5 |
0.75 |
|
|
| 8. |
4.75-mm |
1.0 |
0.50 |
|
|
| 9. |
3.35-mm |
- |
0.30 |
|
|
Table-IV (Minimum weight of Sample for Sieve Analysis)
Clauses 2.4.4, 2.5 & 2.5.2
| Sr. |
Maximum Size Present in Substantial Proportions (mm) |
Minimum weight of Sample to be taken for Sieving (kg) |
| 1. |
63 |
50 |
| 2. |
50 |
35 |
| 3. |
40 or 31.5 |
15 |
| 4. |
25 |
5 |
| 5. |
20 OR 16 |
2 |
| 6. |
12.5 |
1 |
| 7. |
10 |
0.5 |
| 8. |
6.3 |
0.2 |
| 9. |
4.75 |
0.2 |
| 10. |
2.36 |
0.1 |
Reporting of Results
The results shall be calculated and reported as:
- the cumulative percentage by weight of the total sample passing each of the sieves, to the nearest whole number (see Note under 2.6.1); or
- the percentage by weight of the total sample passing one sieve and retained on the next smaller sieve, to the nearest 0.1 percent.
2.6.1 (Graphical Method of Recording Results) - The results of sieve analysis may be recorded graphically on the chart for recording sieve analysis shown in Fig.1
Note - It is recommended that cumulative percentage figures should be used
for comparison with specification requirements, or for reporting results graphically.
Chart for recording the result of Sieve Analysis