Meso Mechanical Analysis of AC Mixture Response

Abstract

Ongoing research into performance modeling of Asphalt Concrete (AC) mixtures using meso mechanics approaches is being undertaken at Delft University of Technology (TUD). The approach has already been successfully employed for evaluating the long term performance of porous asphalt concrete. The work presented in this paper extends the use for predicting the uni-axial response of AC mixtures. The approach demands the meso-scale geometry, the loading and the mechanical behavior of the component materials for the AC mixture to be specified. For this purpose, laboratory tests were first carried out on a bituminous mortar. Then, rectangular AC mixture specimens were prepared in the laboratory. The four sides of the AC specimens were scanned to capture the two dimensional (2D) meso-scale geometry of the mixture. The scanned images were then processed and translated into meso-scale finite element models. Viscoelastic model parameters for the mortar were determined from experimental data. The FE models were then used to simulate the frequency domain response of the AC mixture in a uni-axial mode. Similarly, uni-axial tests were carried out in the laboratory to obtain the frequency domain response of the AC mixture. FE simulated and experimental results were then compared. Good agreements in results have been obtained. The paper thoroughly discusses the obtained results and its implications for developing mixture design tools.