CEMENT CONCRETE ROADS ARE FOUR TIMES COSTLIER THAN THE ASPHALT ROADS FOR WHICH STRENGTHENING OF EDGES & CORNERS OF THE CONCRETE ROADS ESSENTIALLY REQUIRED

The Panchayati Raj Department in the state has started Road Construction by providing the concrete slabs over the base course required with the support of the uniformity of subgrade/base couse laid however not taking into the considerations many variables such as allowable flexural stress in concrete coefficient of subgrade reaction or the sub grade support, wheel load , temperature variations, coefficient of subgrade resistance ie the friction between the slab and the subgrade,distance between the joints required to be considered in designing the thickness of the pavement and many of these variables can not be evaluated precisely, therefore the design calculations give more or less approximate values ,and reliance should be placed on previous experiences. Where the concrete slabs are less than 15 cm thick or where the slabs are on the poor foundation, it is advisable to strengthen their corners by means of hair pin at the designed angle. For more guidelines IRC :15-1970 may be followed to obtain the necessary parameters prescribed by the study of protocol mentioned in the recommendation made by the IRC in this behalf of the cement concrete pavement versus asphalt roads .As such a concrete road with Proper foundation costs about four times that of an asphalt road and concrete roads lasts atleast 20 years against the five years life span of an asphalt road. Damage to a concrete road may be caused by abnormal loading, excessive expansion defective drainage or washouts in the subgrade or settlement. Access of water to the subgrade through joints and other cracks is the commonest cause of failure in a cement concrete road .As such before repair is carried out, the actual cause of the damage must be determined and necessary steps accordingly taken to cure any basic defect in the subgrade drainage system or design of the pavement.