FLEXIBLE PAVEMENT EVALUATION IN INDIA

In India, at present no established scientific method of evaluation of flexible pavement is practised and the CBR method as recommended by Indian Roads Congress (IRC) is still in use to work out the overlay thickness of road structure required to meet the demands of the increased loading and traffic intensity. Evaluation based on maximum surface deflection is not sufficient and it needs to be supplemented by the additional parameter of deflection profile. In this paper an attempt has been made to discuss the development and application of the methodology for flexible pavement evaluation suited to Indian environmental conditions. A methodology for evaluation is proposed, wherein maximum deflection and shape of deflection profile in terms of curvature are employed. A Multichannel recorder with a set of LVDTs has been used, and a deflection profile obtained for semi- full scale model of field conditions. The theoretical model developed has been calibrated using the field deflection data obtained from the Benkelman Beam. The calibrated model yielded vertical tensile strain at the bottom of the surface course under the load axis. The field measurements along with the theoretical model were found to be helpful in developing and standardising the methodology for the evaluation and design of overlay thicknesses more rationally and economically. For the covering abstract of this conference, see IRRD no 843040.