CEMENT : FINENESS BY DRY SIEVING REFERENCE : IS 4031 – (PART – 1) 1996

OBJECT                   TO          CHECK     PROPER     GRINDING     OF     CEMENT     BY MEASURING FINENESS BY DRY SIEVING

IMPORTANCE        During manufacturing, cement must be ground to be uniformly fine

OF TEST                  otherwise concrete needs large amount of water for mixing which results in  bleeding as well as poor workmanship.

APPARATUS          •     Test sieve of non-corrodible metal having 150 mm to 200 mm diam, and 40 mm to 100 mm depth fitted  with 90  µm mesh sieve cloth of  woven stainless steel or other abrasion resistant non- corrodible wires.

•     Suitable tray with lid to fit sieve size.

•     Stoppered jar with blunt ended stirrer rod

•     Weighing balance to weigh upto 10 gms to nearest 10 mg.

•     Nylon or pure bristle brush (25 mm / 40 mm  bristles) for cleaning sieves.

PROCEDURE          Determination of cement residue :

•     Agitate  the  cement  sample  by  shaking  for  2  minutes  in  a stoppered jar to disperse the agglomerates. Wait for few minutes.

•     Stir the resulting powder gently with dry rod to distribute the fines throughout the sample.

•     Weigh  approx.  10  gm  of  cement  and  put  in  sieve  fitted  with bottom tray and top lid.

•     Agitate and shake the sieve thoroughly

•     Weigh the residue – retained on sieve.

•     Clean base of sieve gently by brush to remove fine material.

•     Find out % (R1) of residue in comparison with total weight of sample.

•     Repeat the procedure at least twice till results do not differ by more than 1%.

CALCULATION         Find out mean of observations and express this percentage as R