Dynamic modulus prediction of asphalt concrete using three tensile tests

Abstract

A micromechanical based Discrete Element Model (DEM) was used to simulate dynamic modulus of the asphalt concrete using Uni-axial Tensile (UT) model, Hollow Cylindrical Tensile (HCT) model and Indirect Tensile (IDT) model. The dynamic moduli of the sand mastic and stiffness of aggregate were used as input parameters in the DEM to predict the dynamic moduli of the asphalt concrete. The three-dimensional (3D) internal microstructure of the asphalt concretes (i.e., orientation and distribution of aggregate, mastic and air voids) was obtained through the X-ray CT. The laboratory measured dynamic moduli of asphalt concrete were used to compare predicted dynamic moduli of three different tensile models. UT model was able to predict the asphalt concrete modulus across a range of loading frequencies and test temperatures. HCT model was under-predicted all the given temperatures and frequencies and IDT model slightly over-predicted at −18°C and slightly under-predicted at 4°C.