Reinforced Cement Concrete (R.C.C.) | Definition, Meaning, Uses & Properties of Good R.C.C.
Reinforced Cement Concrete (R.C.C. for short), is a combination of concrete and steel, otherwise known as reinforcement. This is a composite type of construction in civil engineering where the strength capacities of concrete and steel are harnessed together. Concrete is strong in compression but weak in tension. Steel on the other hand, is both good in compression and tension. Due to the elastic modulus of steel, it has better tensile strength than concrete. In the design of R.C. structures, concrete is considered to be devoid of tensile strength. This is because the tensile strength of concrete is highly negligible. Hence, hair cracks often occur in tensile zones of concrete.
To cater for this, steel is normally provided in the tensile zones of R.C.C. structures to take the tensile stresses developed in the structure. Because the bond between concrete and steel is good and the tensile strength thereof is high, steel is used for this purpose.
Steel reinforcements are usually in the form of mild steel or ribbed steel bars of 6mm to 32mm diameter. A cage of reinforcement is prepared and kept in a formwork. Fresh concrete is poured. After the concrete hardens, the formwork is removed. The composite member formed is known as R.C.C. i.e, Reinforced Cement Concrete. This member is structurally strong both in compression and tension.
Requirements & Properties of Good Reinforced Concrete Construction (R.C.C.)
- Green concrete (i.e. fresh concrete) should be workable. It should have the ability to be moulded to any shape and size.
- It should have good fire resistance. Fire resistance of R.C.C. could be enhanced by providing adequate cover for various exposure conditions and a good solid mix.
- Hair cracks developed within the member should be within the permissible limit.
- There should be adequate concrete cover to protect the reinforcement from corrosion.
- It should not spoil serviceability requirements by being excessively deflective.
- It should be capable of withstanding the expected tensile & compressive loads, and should be strong to withstand the bending moments and shear forces too.
Uses of Reinforced Cement Concrete (R.C.C.)
R.C.C. is commonly used for building works and construction. The following are some of the important uses or applications of R.C.C.:
R.C.C. is used in the construction of common structural elements like columns, beams, footings, slabs, lintels, stairs, roofs, balconies, eaves and sunshades.
It is used in the construction of storage structures like dams, tanks, bins, silos and bunkers.
It is used for paving roads and airports.
It is used for the construction of large structures like retaining walls, canals, docks and harbours, tunnels, bridges, and under-water structures.
It is used for precast structures like electric poles, railway sleepers, etc.
It is used for the construction of tall structures like chimneys, towers and multistorey buildings.
It is used in the construction of atomic plants for the prevention of radiation. R.C.C walls, 1.5m to 2.0m thick may be built for this purpose.