1.1 FINENESS

AIM

To determine the fineness of cement by dry sieving as per

IS: 4031 (Part 1) - 1996.

PRINCIPLE

The fineness of cement is measured by sieving it through a

standard sieve. The proportion of cement, the grain sizes of

which, is larger than the specified mesh size is thus determined.

APPARATUS

i) 90µm IS Sieve

ii) Balance capable of weighing 10 g to the nearest 10 mg

iii) A nylon or pure bristle brush, preferably with 25 to 40 mm

bristle, for cleaning the sieve

PROCEDURE

i) Weigh approximately 10 g of cement to the nearest 0.01 g and

place it on the sieve.

ii) Agitate the sieve by swirling(घूर्णन), planetary(ग्रहिये) and linear(रेखीये)

movements, until no more fine material passes through it.

iii) Weigh the residue and express its mass as a percentage R1,

of the quantity first placed on the sieve to the nearest 0.1

percent.

iv) Gently brush all the fine material off the base of the sieve.

v) Repeat the whole procedure using a fresh 10g sample to

obtain R

2. Then calculate R as the mean of R1 and R2 as a

percentage, expressed to the nearest 0.1 percent. When the

results differ by more than 1 percent absolute, carry out a

third sieving and calculate the mean of the three values.

REPORTING OF RESULTS

Report the value of R, to the nearest 0.1 percent, as the residue

on the 90µm sieve.