Load Equivalency Factors for Asphalt Pavements

Load Equivalency Factors for Asphalt Pavements

Dr. Sameh Zaghloul and Professor Thomas D. White

Abstract

In this paper Load Equivalency Factors (LEF) for asphalt pavements with granular base as well as for full depth asphalt pavements are presented. These LEF's are developed for the overload permitting study and are based on equal total permanent (plastic) deformation (TPD) at the pavement surface. A three-dimensional dynamic finite element model (3D-DFEM) was used to analyze flexible pavements. This 3D-DFEM has the capability to simulate truck loads moving at different speeds. Also, it can model paving materials realistically as elastic, elastic-plastic, viscoelastic and plastic materials. The 3D-DFEM predicts both the elastic and plastic pavement response for one or more load applications. The 3D-DFEM was verified in two steps; first for static, linear elastic analysis and then for dynamic, non-linear anlysis.