How to perform standard consistency test of cement
Cement is tested with the following methods.
Standard Consistency Test
In this construction article, discussion is made on standard consistency test.
The standard consistency of a cement paste stands for the consistency that will allow a vicat plunger with 10 mm diameter and 50 mm length to infiltrate to a depth of 33-35 mm from the head of the mould.
This method is applied to determine the proportion of water necessary to form a cement paste maintaining standard consistency. It is also known as normal consistency (CPNC).
Initially, select about 500 gms of cement & water of 24% by weight of cement.
Vicat’s mould should be filled with it within 3 to 5 minutes.
As soon as it is filled, shiver the mould to throw out the water.
A standard plunger with 10 mm diameter and having length 50 mm is fastened and brought down to keep in contact with the surface of the paste and loosed swiftly.
Record the reading as per depth of penetration of the plunger.
The trial should be operated constantly by selecting various water cement proportions unless the plunger is pushed for a depth of 33 to 35 mm from top.
This specific ratio is defined as ratio of water necessary to form cement paste maintaining standard consistency.
It is normally illustrated as P.
Performed in a constant temperature of 270 + 20 C.