TYPES OF CEMENT, ITS COMPOSITION AND USES
The following are the types of cement that are in practice:
1. Rapid Hardening Cement
2. Quick setting cement
3. Low Heat Cement
4. Sulphates resisting cement
5. Blast Furnace Slag Cement
6. High Alumina Cement
7. White Cement
8. Coloured cement
9. Pozzolanic Cement
10. Air Entraining Cement
11. Hydrographic cement
Table below shows different types of cement, their composition and uses:
Types of Cement
Rapid Hardening Cement
Increased Lime content
Attains high strength in early days it is used in concrete where form work are removed at an early stage.
Quick setting cement
Small percentage of aluminium sulphate as an accelerator and reducing percentage of Gypsum with fine grinding
Used in works is to be completed in very short period and concreting in static and running water
Low Heat Cement
Manufactured by reducing tri-calcium aluminate
It is used in massive concrete construction like gravity dams
Sulphates resisting Cement
It is prepared by maintaining the percentage of tricalcium aluminate below 6% which increases power against sulphates
It is used in construction exposed to severe sulphate action by water and soil in places like canals linings, culverts, retaining walls, siphons etc.,
Blast Furnace Slag Cement
It is obtained by grinding the clinkers with about 60% slag and resembles more or less in properties of Portland cement
It can used for works economic considerations is predominant.
High Alumina Cement
It is obtained by melting mixture of bauxite and lime and grinding with the clinker it is rapid hardening cement with initial and final setting time of about 3.5 and 5 hours respectively
It is used in works where concrete is subjected to high temperatures, frost, and acidic action.
It is prepared from raw materials free from Iron oxide.
It is more costly and is used for architectural purposes such as pre-cast curtain wall and facing panels, terrazzo surface etc.,
It is produced by mixing mineral pigments with ordinary cement.
They are widely used for decorative works in floors
It is prepared by grindin pozzolanic clinker with Portland cement
It is used in marine structures, sewage works, sewage works and for laying concrete under water such as bridges, piers, dams etc.,
Air Entraining Cement
It is produced by adding indigenous air entraining agents such as resins, glues, sodium salts of Sulphates etc during the grinding of clinker.
This type of cement is specially suited to improve the workability with smaller water cement ratio and to improve frost resistance of concrete.
It is prepared by mixing water repelling chemicals
This cement has high workability and strength