Why water is not used to find specific gravity of cement?

If a cement has exposed to extreme moisture content then the specific gravity of cement will differ because of the moisture content present in the pores. Every material has solid particles and pores which may contain water in it. So it is essential to determine the specific gravity of cement before using it.

Water is not used in the testing of specific gravity of cement because cement reacts with water and forms compounds. Thus, the quantities measured prior to the commencement of test will not be same after the test.

Specific gravity of any material is defined as the ratio of weight of a volume of a material to the weight of same volume of water at particular temperature. So in this test the quantities are very important. Water is not used in testing of specific gravity of cement because cement reacts with water and form compounds. Thus , the quantities measured prior to the commencement of test will not be same after the test. Therefore kerosene which is inert (non-reactive) with cement is used. We should observe here that we calculate the specific gravity of cement with respect to kerosene and convert it with respect to water by using 0.79 (specific gravity of kerosene) in the formula of the same.