Three-dimensional microstructural modelling of coupled moisture–mechanical response of asphalt concrete

Abstract

Three-dimensional (3D) microstructural representation of asphalt concrete subjected to moisture diffusion and mechanical loading is simulated and analysed. The continuum moisture–mechanical damage mechanics framework and the moisture damage constitutive relationship developed by the authors are used in this study to couple the detrimental effects of the mechanical loading and moisture diffusion on the complex response of asphalt concrete. A 3D finite element (FE) microstructural representation of a typical asphalt concrete is used for these simulations. The 3D microstructure is reconstructed from slices of two-dimensional X-ray computed tomography images that consist of the matrix and the aggregates. Results show that the generated 3D FE microstructure along with the coupled moisture–mechanical constitutive relationship can be effectively used to simulate the overall thermo-hygro-mechanical response of asphalt concrete. The analyses provide insight into the impact of the microstructure on the overall response of asphalt concrete.

Keywords::

• moisture-induced damage
• microstructural simulations
• moisture–mechanical coupling
• asphalt concrete pavements

Acknowledgements

The authors acknowledge the financial support provided by Federal Highway Administration through the Asphalt Research Consortium (ARC). Moreover, the authors acknowledge the Texas A&M Supercomputing Facility for providing computing resources useful in conducting the research reported in this article.