Category: 6: CEMENT MATRIAL

Portland cement comes from elements found in limestone, including aluminum, calcium, and silica. Lime and silica make up about 85 percent of cement. Other ingredients in cement usually include clay and silica, or silica sand.

4CaO·Al2O3·Fe2O3 = calcium alumino ferrite. C-S-H. Calcium silicate hydrate, a colloidal and mostly amorphous gel with a variable composition; this is the major hydration product of Portland cement, constituting approximately 70 percent of the paste, and is the phase providing most of the strength and binding.

The correct answer is Limestone. Limestone is the main ingredient of cement. Limestone is a sedimentary type of rock naturally found on earth. Limestone rock primarily contains calcium carbonate i.e CaCO3.

Cement is a fine, soft powder used as a binder because it hardens after contact with water. It is produced from a mixture of limestone and clay that’s charred and then ground u