DESIGN OF THE RIGID CEMENT CONCRETE ROAD STRUCTURES

CEMENT CONCRETE ROADS:-- 10 cm thick concrete slabs laid over 15 cm well consolidated existing water bound macadam crust have been found adequate to stand an axle load of 8100 kg and heavy cart traffic.It in very essential to have a good solid foundation of well consolidated and non observative material under the concrete road .A concrete slab being rigid type of construction,is liable to crack over a yielding and flexible base when loaded .The most important property of required of a base or subgrade is its equal bearing power all over and not its actual bearing value.The load carrying capacity of the concrete road structure lies mainly in the structural rigidity of the slab and the uniformity of the subgrade support. It is therefore necessary to prepare the base in such a way that concrete slabs are supported as uniformly as possible As such the base, subbase or subgrade together act as a unit for supporting the concrete pavement.A plain concrete slab in which the direction in any direction exceeds 4.5 meters is liable to crack and where the slabs are reinforced longitudinally and transversely with equal amount of steel,width can be increased up to seven meters.For more clarification recommended IRC 15 -1970 may be consulted required for the construction of the concrete road structure