Mechanistic Modeling of Rutting in Asphalt Pavement Analyzer (APA) Tests

Abstract

Asphalt Pavement Analyzer (APA) is one of the accelerated loaded wheel testers which allow for the Hot Mix Asphalt (HMA) specimens to be subjected to simulated moving wheel loads under controlled temperature and moisture conditions. The purpose of this paper is to present the development of a Finite Element Method (FEM) simulation technique for the APA tests. The visco-elastic and visco-plastic constitutive model for the HMA was briefly described. The FEM simulation technique was outlined. The validity of the FEM simulation technique has been presented by providing the comparisons between the FEM predictions and actual APA test results for a large number of different types of HMA mixtures, including polymer modified HMA. Furthermore, the APA test variables, including the wheel speed, the load of the wheel, and the temperature, was varied in the FEM simulation to identity the important controlling factors in testing rutting behavior of the HMA. The developed computational algorithm will be very useful in the future for linking the APA rut depth and the corresponding field rut depth found in the actual pavement under site specific traffic and environment conditions.