DEM Simulation of Laboratory Compaction of Asphalt Mixtures Using an Open Source Code

Abstract

Asphalt mixture compaction is an important procedure of asphalt pavement construction and can significantly affect the performance of pavement. In recent years, the finite element method (FEM) has been utilized by researchers to study asphalt mixture compaction. However, FEM is a continuum approach and unable to take into account the slippage and interlock of aggregates during the compaction process. With its inherent advantages, the discrete element method (DEM) is a more suitable tool than FEM to simulate asphalt mixture compaction. In this study, an open source DEM code was applied to simulate three types of hot-mix asphalt (HMA) compaction for the first time: superpave gyratory compaction, vibration compaction, and kneading compaction. A viscoelastic contact law was used for the simulation and the parameters were obtained through nonlinear regression analysis of dynamic modulus test results. The DEM simulation results show good agreement with lab compaction test results, which indicates that DEM is a reasonable tool to simulate asphalt mixture compaction and has tremendous potential to help guide asphalt mixture compaction.