Cement is produced by burning a mixture of calcium and clay material at very high temperature then grinded to produce fine powder.
Types of cement.
Cement comes in many varieties. Some are briefly explained below.
Ordinary portland cement;
The most used type of cement in general concrete construction. It is suitable when there is no danger of exposure to sulphates in the soil.
Quick setting cement;
Quick setting cement is produced by reducing the percentage of gypsum and adding a small amount of aluminium sulphate during production. This type of cement starts setting around 5 minutes and hardens within 30 minutes. Quick setting cement is used to produce concrete for underwater construction.
it is made from oxides of manganese,iron and chlorium. It is used for plastering, ornamental works, fixing of marbles and tiles.
Rapid hardening cement;
This type of cement gains strength earlier than ordinary Portland cement and consequently speeds up construction activity.
Coloured cement is produced by mixing pigments with ordinary Portland cement. Pigments such as colbalt produces blue colour, iron oxide produces brown, red or yellow colours.
Low heat cement;
When heat produced by hydration of cement does not get easily dispersed, it may give rise to cracks, hence in such situations it is preferable to use low heat cement.
High alumina cement;
This type of cement is produced from a mixture of lime and banxite. It is resistant to sulphate and acid attack.it is used in underwater construction.
Acid resistant cement;
This is cement made by adding acid resistant materials such as quartz, quartzite, sodium silicate or soluble glass. Acid resistant cement is commonly used in construction of chemical factories.