Parametric Model Study of Microstructure Effects on Damage Behavior of Asphalt Samples

This paper presents a computational modeling study of the microstructural influence on damage behavior of asphalt materials. Computer generated asphalt samples were created for numerical simulation in indirect tension and compression testing geometries. Our previously developed micromechanical finite element model was used in the simulations. This model uses a special purpose finite element that incorporates the mechanical load-carrying response between neighboring aggregates. The element was developed from an approximate elasticity solution of the stress and displacement field in a cementation layer between particle pairs. The computational model establishes a network of such elements to simulate an asphalt mass. Continuum damage mechanics was then incorporated within this scheme leading to the construction of a micro-damage model capable of predicting typical global inelastic behavior found in asphalt materials. A series of model asphalt samples have been generated and simulated with controllable microstructure variation in an effort to determine the effects of particular microstructural variables on the material response. These simulations explored the relationship between microstructure parameters and damage behavior of particular asphalt samples.