Types of concrete and its characteristics
Concrete belongs to a composite material where a binding material provided in water on solidification to unite the static particles containing properly graded fine and coarse aggregates.
Cement and lime are generally applied as binding materials while sand & cinder are utilized as fine aggregates. Crushed stones, gravel, broken bricks and clinkers are utilized as coarse aggregates.
Given below, the characteristics of standard concrete :-
Strength – The concrete should have the ability to resist the probable stresses. The concrete has good strength against compression but less strength against tension.
Stability – It should be long-lasting to give protection against harmful effect of weather.
Density – The concrete should be compacted perfectly to avoid hollows or voids. It should weigh 3000 kg/cu.m
Water tightness – Water tightness of concrete plays an important role for water retaining structures like dams, elevated tanks and water reservoir as moisture can’t enter inside the RCC and no erosion and leakage occur. As a result, ultimate failure of the structure is stopped.
Workability – The concrete should be simply workable.
Resistance against wear and tear – If concrete is utilized in floors and in the construction of roads, the concrete can resist destructive forces.
Concrete Types: Concrete is segregated as follow-
1. Based on the binding material applied in concrete.
2. Based on the design of concrete.
3. Based on purpose of concrete.
Depending on binding material applied, concrete is categorized as follow :-
Cement Concrete – In this type of concrete, the ratio of constituents is 1 part cement, 1-8 part sand, 2-16 parts course aggregates.
Lime Concrete – The concrete comprising of lime, fine aggregates and coarse aggregates which are blended in proper ratios with water is known as lime concrete.
Under this type of concrete hydraulic lime is normally utilized as a binding material, sand and cinder are utilized as fine aggregate and broken bricks & gravel are utilized as coarse aggregates.
Based on design, concrete is segregated as follow :-
Plain Cement Concrete – In this type of concrete, no reinforcement is provided. The concrete has good strength against compressive stresses but weak in bearing tensile stesses.
Reinforced Cement Concrete (RCC) – In this type of concrete, reinforcement is implanted for bearing tensile stress. Here, steel reinforcement is normally applied in the form of round bars with 6mm to 32mm dia. This concrete has good strength in bearing tensile, compressive and shear stresses. Normal ratios of components in RCC are 1 part of cement, 1-2 parts of sand, 2-4 parts of crushed stones or gravel.
Pre-stressed cement concrete (PCC) – In this type of concrete high compressive stresses are artificially forced prior to their actual application. Here, high compressive stresses are forced by pre-tensioning the reinforcement prior to place the concrete and the reinforcement is discharged when the final setting of the concrete occurs.
Depending on purpose, the concrete is segregated as vacuum concrete, air entrained concrete and light weight concrete.