Effect of traffic load on pavement serviceability

Since much of the required infrastructure in the U.S. is already in place, the emphasis has been shifting to maintaining and rehabilitating existing roads. An important prerequisite for a proper maintenance and rehabilitation strategy is the knowledge of how traffic loads affect the pavement condition at different ages and under different vehicular and environmental conditions. Traditionally, empirical relations have been used to estimate the performance of various maintenance and rehabilitation treatments for the purpose of allocating funds. The present paper provides a rational technique to estimate the change in pavement serviceability caused by traffic loads under different pavement roughness and vehicle conditions. Once the condition is known at different times throughout the life of the pavement, a proper maintenance and rehabilitation strategy can be established. In this study the vehicle dynamic model, COMPAS, was used to estimate the dynamic wheel forces applied on the pavement surface under different roughness levels, vehicle types, vehicle speeds, and suspension types. The dynamic response of the pavement and the permanent deformation accumulated on the pavement surface were calculated at small intervals after different load repetitions using the three-dimensional finite element program ABAQUS. Starting with a new pavement, the pavement profile and serviceability after different load repetitions were determined. Mechanistic-based pavement performance models were developed for typical pavement sections. The developed performance models can be used to estimate the number of load repetitions that cause the pavement to reach specific conditions throughout its service life. This information is essential for developing rational maintenance and rehabilitation strategies at the network level.