Development of structural condition assessment model for flexible pavement based on LWD and GPR measurements

Abstract

The structural condition assessment of flexible pavement can be done very conveniently and rapidly using non-destructive testing (NDT). The conventional NDT in-situ pavement evaluation devices require excessive time and resources. Initially, light weight deflectometer (LWD) has been used to measures the deflection and stiffness of bound/unbound pavement layers. Beside LWD produces safe, reliable, rapid and cost-effective in-situ measurements. This paper presents a structural condition assessment model for thin flexible pavement based on LWD and ground penetrating radar (GPR) measurements. An increase in LWD structural index is indicative of the increase in deflection magnitude and scattering through a road section. Case studies were carried out to examine the model and validate by using effective structural number. Result of average surface deflection, 90th percentile surface modulus and pavement thickness reveals good agreement when compared with the prior studies and core samples. The outcome of the structural index model can be said as a quick and simple screening tool at the project or network level to identifying structurally deficient pavements.