A Study of Nonlinear Tire Contact Pressure Effects on HMA Rutting

Abstract

The Indiana Department of Transportation/Purdue University accelerated pavement testing (APT) facility has been utilized in a number of studies of hot mix asphalt (HMA) rutting performance. The benefit of using APT is that rutting performance can be established in a few days of testing. Finite element (FE) models have been developed for relating APT to in‐service pavement performance. Factors addressed in the models include pavement geometry, boundary conditions, materials, loads, test conditions, and construction variables. Determining the effects of these factors provides a means for better interpreting APT test results and HMA rutting performance. A detailed analysis using 3D and 2D FE has been made of tire/pavement contact pressure effects on rutting. The analyses include tread pattern and constant and varying contact pressure. A creep model is used to represent the HMA time‐dependent material behavior. Based on test data, the material constants in the creep model were back calculated. Results of the FE studies show that the creep model can successfully characterize pavement material behavior through a reasonable approximation of loading and other factors.