Effect of asphalt film thickness on shear mechanical properties of asphalt-aggregate interface

This paper focuses on the effect of asphalt film thickness on the shear mechanical properties of asphalt aggregate interface. Firstly, an experiment controlling the asphalt film thickness was designed to build the relationship between the asphalt film thickness and the molding load. Then, a shear test was carried out to characterize the properties of asphalt-aggregate interface under different asphalt film. The stress displacement curves showed two modes: single and double wave peaks. The probability relationship between the two modes and the asphalt film thickness was established. Finally, the influence of asphalt film thickness on the shear failure mechanism of asphalt-aggregate interface phase was analyzed. Results show that an experimental method for controlling the asphalt film thickness is effectively developed. When the asphalt film thickness is 23.6 mu m and 219 mu m, only the single wave peak mode appears in the stress-displacement curves. Otherwise, the stress-displacement curves of comparison experiments with other thicknesses show single wave peak and double wave peak, respectively. The double peak probability is found to be related to the asphalt film thickness. The asphalt film thickness is the key point which determines the shear failure behavior of the aggregate-asphalt interface phase, such as cohesive failure or adhesion failure. (C) 2020 Elsevier Ltd. All rights reserved.