A cement is a binder, a substance that sets and hardens as the cement dries and also reacts with carbon dioxide in the air dependently, and can bind other materials together. Cement is obtained by burning and crushing stones containing clay, carbonates of lime and some amount of carbonates of magnesia. Cements used in construction can be characterized as being either hydraulic or non-hydraulic, depending upon the ability of the cement to be used in the presence of water. Non-hydraulic cement will not set in wet conditions or underwater, and is attacked by some aggressive chemicals after setting.
Physical properties of cement
- It gives strength to the masonry.
- It is an excellent binding material.
- It is easily workable.
- It offers good resistance to moisture.
- It possess good plasticity.
- It stiffens and hardens early.
Constituents of cement
- Lime
- Silica
- Alumina
- Calcium Sulphate
- Iron oxide
- Magnesia
- Sulphur
- Alkalies
Types of cement
- Blast furnace cement
- Pozzuolana cement
- Quick setting cement
- Rapid hardening cement
- High alumina cement
- Low heat cement
- Sulphate resisting cement
- White cement
- Hydrophobic cement
- Acid resisting cement
- Coloured cement
- Expanding cement
