Development of a Multiaxial Viscoelastoplastic Continuum Damage Model for Asphalt Mixtures

摘要

This report highlights findings from the FHWA DTFH61-05-H-00019 project, which focused on the development of the multiaxial viscoelastoplastic continuum damage model for asphalt concrete in both compression and tension. Asphalt concrete pavement, one of the largest infrastructure components in the United States, is a complex system that involves multiple layers of different materials, various combinations of irregular traffic loading, and various environmental conditions. The performance of this structure is closely related to the performance of asphalt concrete. To predict the performance of asphalt concrete with reasonable accuracy, a better understanding of its deformation behavior under realistic conditions is urgently needed. Over the past decade, the authors have been successful in developing uniaxial material models that can accurately capture various critical phenomena such as microcrack-induced damage that is critical in fatigue modeling, strain-rate temperature interdependence, and viscoplastic flow, which is critical for high temperature modeling. The resulting model is termed the viscoelastoplastic continuum damage model. However, to consider the complicated nature of in-service stress states, a multidimensional model is needed. To predict the performance of the real pavement structures, it is also important to incorporate the material model in a pavement model that considers the vehicle and climatic loads as well as the boundary conditions; the in-house finite element package has been developed for this purpose.