TYPES OF CEMENTS
There are various types of cements:‑
1) PORTLAND CEMENT
It is again divided into various types depending on the amounts of the clinker.
REGULAR PORTLAND CEMENT
It is used for general concrete construction.
ii) MODERATE HEAT OF HARDENING AND SULFATE RESISTING PORTLAND CEMENT
It is used where moderate heat of hydration is required.
iii) HIGH EARLY STRENGTH (HES) CEMENT
This gives quicker hardening.
iv) LOW-HEAT PORTLAND CEMENT.
v) SULFATE-RESISTING PORTLAND CEMENT.
2) POZZOLAN CEMENT
Italians used 2-4 parts of Pozzolan with 1 part of hydrated lime on fine grinding give this cement. Pozzolan are volcanic tuffs.
- HIGH-ALUMINA CEMENT OR CALCIUM ALUMINATE CEMENT
It is manufactured by fusing a mixture of limestone and bauxite. It is resistance to seawater and sulfate bearing water.
- SPECIAL OR CORROSION-RESISTING CEMENT
There are many kinds of special cements are described in the literature but the furnace phenolic, sulfur and silicate cements are the most important.
- CONTROLLED CEMENTS
The controlled is used to prevent shrinking and cracking upon setting with the addition 10 to 20% of calcium sulfoaluminate in Portland cement, the tendency of concrete to crack can be virtually eliminated.