Impacts of Aggregate Morphological Characteristics on Asphalt Mixture Performance Based on Experimental Tests

摘要

This paper presents an experimental approach to investigate the influence of aggregate shape and angularity on the mixing property and mechanical behaviors of asphalt mixtures. A digital image technique was employed to quantify aggregate shapes and angularities. Seven different asphalt mixtures were tested by the mixing rheometer to evaluate their mixing behaviors. Creep and dynamic modulus tests of four asphalt mixtures were performed to measure creep deformation and dynamic modulus. The testing results were linked to the corresponding aggregate morphological index. It is indicated that mixing torques increase with the increasing shape index and angularity. In terms of creep deformation and dynamic modulus, natural aggregates were better than glass aggregates, and the aggregates with bigger-shape index and less-angularity will increase the creep deformation and decrease the dynamic modulus.