Non-uniqueness of micro deformation of asphalt concrete

Abstract

Asphalt concrete as a bonded granular material demonstrates duality in response to external load. At macro level, the material behaves like a continuum due to the binder. At micro level, loads are transmitted through particle contacts and stress concentrations become very complicated due to the involved packing pattern of aggregates and void distributions. To investigate this duality, a set of tests on asphalt concrete under repeated load has been observed at both macro level and micro level. At macro level, the magnitude and the pattern of permanent deformation were measured. At micro level, strain localization zones and crack distributions were captured as digital images. Four cross sections from one specimen were measured and the measurements were compared. The comparisons show that with the same macro responses of permanent deformation, the strain localization pattern and crack distribution are very different. This phenomenon has important implications to constitutive modeling micromechanics are presented. For the covering abstract see ITRD E117423.