Necessity of Adding Gypsum (CaSO4) in Cement Manufacture - Civil Engineering

Thursday, 20 June 2019

Necessity of Adding Gypsum (CaSO4) in Cement Manufacture

Necessity of Adding Gypsum (CaSO4) in Cement Manufacture

Portland cement as obtained from grinding clinkers usually sets and hardens immediately after the addition of water. In order to slow down the setting time of cement, gypsum @ 3% to 4% is added during the process of clinker grinding.

But, if the quantity of gypsum is more, the cement becomes very slow setting. It also hardens slowly which results delay in the removal of formwork. Gypsum combines with tricalcium aluminate and prevents flash setting.
But, if more gypsum is added with cement, the excess amount after combining with tricalcium aluminate remains free in cement. It expands and makes the cement unsound.
Read Also:

No comments:

Post a Comment