For Students
Various tests to which cements must conform are laid down in national cement specifications to control the fineness, soundness, setting time, and strength of the cement. These tests are described in turn below. Fineness was long controlled by sieve tests, but more sophisticated methods are now largely used. The most common method, used both for control of the grinding process and for testing the finished cement, measures the surface area per unit weight of the cement by a determination of the rate of passage of air through a bed of the cement. Other methods depend on measuring the particle size ...(100 of 4248 words)