1. Limestone, Clay
2. When clay and lime are strongly heated together they fuse and react to form cement clinker. This clinker is mixed with 2- 3% by weight of gypsum to form cement.
3. Dicalcium silicate (Ca2SiO4) – 26%,
tricalcium silicate (Ca3SiO5) – 51% and
tricalcium aluminate (Ca3Al2O6) – 11%
4. When mixed with water, the setting of cement takes place to give a hard mass. This is due to the hydration of the molecules of the constituents and their rearrangement.