Fineness of Cement by Dry Sieving (Very Simple Procedure)

To find fineness of cement by dry sieving method. In this method the cement sample is sieved dry on IS sieve no. 9. The residue left is expressed as percent of weight of sample, and in an indirect measure of fineness of cement.

Apparatus:

1. 90 micron IS sieve

2. Weighing balance (2kg) accurate to 0.1g, with weights

3. Bristle brush 25mm size.

Material: Cement sample weighing about 100g.

Procedure:

1. Weigh cement sample accurately and record weight W1. Place the sample on IS sieve no.9 (It is preferable to take W1= 100g for simplifying calculations).

2. Break air set humps in the sample with fingers.

3. Hold the sieve in both hands and sieve with a gentle wrist motion without spilling the cement and keeping cement well spread on the screen. Carry out continuous circular motion of the sieve for a period of 15 minutes.

4. Collect the residue left on the sieve, using brush if necessary, and weigh and residue. Let the weight of residue be W2.

Observations and Calculations:

1. Weight of the cement sample = W1 gms.

2. Weight of residue = W2 gms.

    Hence,  Percentage residue = P = (W2/W1) x 100 %

Results: Percent of residue of cement sample by dry sieving = P %. It is less than/ more than 10%

Requirement: As per IS 269-1976, the residue by weight on 90 micron IS sieve by dry sieving should not exceed 10% by weight in case of Ordinary Portland Cement. Coarser material more than 10% signifies less fine cement and vice versa.

Conclusion:

The given sample of cement contains less than/ more than 10% by weight of materials coarser than 90 micron sieve. Therefore it satisfies/ does not satisfy the criteria as specified by IS.