An Inverse Approach for Evaluating the Properties of Asphalt Concrete Using the APA Test

Rutting is one of the most serious distresses for asphalt pavement. The occurrence of rutting affects the performance of the pavement. Simulative tests including Asphalt Pavement Analilzer (APA) tests have been widely used to evaluate the rutting potential of Asphalt Concrete (AC). However; they usually cannot give fundamental properties of AC due to the complex stress and strain fields. In this study, a computational simulation method for the APA test was developed to predict the rutting potential of AC through a viscoplasticity model and three-dimensional (3D) Finite Element Method (FEM). The model material parameters such as the elasticity modulus, yielding stress, and rutting factor (f) were obtained through an inverse method. Sensitivity of the material parameters on the influence of the rutting behavior was also evaluated. The comparison between APA test results and the model simulation indicates that the model can capture rutting behavior of AC very well. The inverse technique enables characterization of fundamental material properties through simulative tests and saves tremendous efforts for calibration of advanced models. The computational simulative test also makes it possible to simulate rutting tests at different scales.