To determine the quantity of water required to produce a cement
paste of standard consistency as per IS: 4031 (Part 4) - 1988.
The standard consistency of a cement paste is defined as that
consistency which will permit the Vicat plunger to penetrate to a
point 5 to 7mm from the bottom of the Vicat mould.
FIG. 2 : VICAT APPARATUS
i) Vicat apparatus conforming to IS: 5513 - 1976
ii) Balance, whose permissible variation at a load of 1000g
should be +1.0g
iii) Gauging trowel conforming to IS: 10086 - 1982
i) Weigh approximately 400g of cement and mix it with a
weighed quantity of water. The time of gauging should be
between 3 to 5 minutes.
ii) Fill the Vicat mould with paste and level it with a trowel.
iii) Lower the plunger gently till it touches the cement surface.
iv) Release the plunger allowing it to sink into the paste.
v) Note the reading on the gauge.
vi) Repeat the above procedure taking fresh samples of cement
and different quantities of water until the reading on the
gauge is 5 to 7mm.
REPORTING OF RESULTS
Express the amount of water as a percentage of the weight of
dry cement to the first place of decimal.