Types of Concrete:

Concrete plays very important role in construction industry as a construction material. It is a stone like hard material obtained by mixing cement, sand (fine aggregate), coarse aggregate and water in some specific proportions. The concrete can be mould in any desired shape in plastic stage. The chemical reaction between cement and water binds the aggregate into a solid mass. Concrete's strength increases with age. Cement, sand (fine aggregate) or water combines to form mortar, which fills the voids in coarse aggregate to form concrete.

Plain Cement Concrete (PCC) has considerable strength in compression but it has very little strength in tension. Thus, the use of PCC is generally restricted to situations, where high compressive strength and weight are of the primary requirements. PCC is, thus, used in the construction of bed blocks, massive gravity dams, columns, dock-walls, arches and gravity retaining walls and etc.

As concrete is weak in tension, steel bars (reinforcement) are used in concrete. Such a concrete is called as Reinforced Cement Concrete (RCC). Steel reinforcement is generally placed in the tension zone of the member before concreting is done. A few times to decrease the size of concrete member or if the concrete member is subjected to reversal of stresses then steel reinforcement might be provided in compression zone also.

Cement concrete could be defined as a mixture of cement, sand, coarse aggregate and water in some specified proportion.

A few special ingredients known as 'Admixtures' are also added to improve some properties of concrete.

The fresh mixture of sand, cement, coarse aggregate and water in plastic stage are called as 'Fresh Concrete'.

Since time passes, the mixture of ingredients of fresh concrete gets hardened which is called as hardened concrete.