|Class 11 Chemistry The S Block Elements||Cement|
Composition of Portland cement
Strong heating of clay andlime results in their fusion followed by the formation of cement clinker which is then mixed with 2-3% by weight of gypsum(CaSO42H2O). This leads to the formation of cement.
Dicalcium silicate (Ca2SiO4) = 26%,
Tricalcium silicate (Ca3SiO5) = 51%
Tricalcium aluminate (Ca3Al2O6) = 11%
Addition of water to cement hydrates the molecules of the constituents. Gypsum is added in order to slow down the process of setting of the cement to make it get hardened.
Fig. Cement used to build buildings, walls, bridges