08-08-2014, 10:59 AM
TESTS FOR FINENESS (IS 4031 )
The first requirement is that 90% of cement should pass IS 90 mircons. Indian standard also specifies fineness test by blaine’s air permeability method as described in IS 4031-1968
95% of cement particles are smaller than 45 micrometer, with the average particle around 15 micrometer.
Fineness of cement affects heat released and the rate of hydration.
![[Image: blaine.jpg]](http://www.frontdesk.co.in/big/cm/blaine.jpg)
The principle is based on relation between the rate of flow of air through a cement bed and surface area of particles comprising the cement bed of given porosity
It should be at least 225 m2/kg
More is the fineness of cement more will be the rate of hydration.
Thus the fineness accelerates strength development principally during the first seven days
The first requirement is that 90% of cement should pass IS 90 mircons. Indian standard also specifies fineness test by blaine’s air permeability method as described in IS 4031-1968
95% of cement particles are smaller than 45 micrometer, with the average particle around 15 micrometer.
Fineness of cement affects heat released and the rate of hydration.
The principle is based on relation between the rate of flow of air through a cement bed and surface area of particles comprising the cement bed of given porosity
It should be at least 225 m2/kg
More is the fineness of cement more will be the rate of hydration.
Thus the fineness accelerates strength development principally during the first seven days