Effect of Microstructure on the Static and Dynamic Behavior of Recycled Asphalt Material

摘要

This report describes the third year's research activities of a project dealing with the micromechanical behavior of asphalt materials. The project involved both theoretical/numerical modeling and experimental studies that were applied to investigate the micromechanical behavior of asphalt material. The modeling work has employed finite element techniques to develop a microstructural model of heterogeneous asphalt materials. The model simulates the load transfer between aggregates using a micro-frame network scheme whereby the binder-aggregate system is replaced by an equivalent network of finite elements. The current work extended the model simulation to include nonlinear, softening behavior using damage mechanics theory. This concept developed a softening element that was capable of predicting the large inelastic response of asphalt materials. The formulation was implemented using the ABAQUS commercial FEA code. Model results for the overall sample response compared favorably with experimental data for indirect tension tests. Also, preliminary comparisons of sample micro- fracture/failure behaviors compared well with observed experimental photographic data. Additional experimental work included characterization studies of binder samples.