Effect of image-based coarse aggregate morphology on shear resistance of asphalt surface

coarse aggregate morphology;  asphalt mixture;  shear resistance;  Uniaxial penetration test;  Image analysis

The morphology (shape characteristics) of mineral aggregates quantified by contour shape, angularity and surface texture have a significant influence on the properties of asphalt mixtures. In order to study the influence of coarse aggregate morphology on the shear performance of asphalt surface layer, the coarse aggregate morphology was regarded as the primary factor, the shape parameters of coarse aggregate based on image were defined, and the shape parameters of five groups of coarse aggregates with different particle shape characteristics were obtained by using the prepared image processing procedure, and the influence of coarse aggregate morphological parameters on the shear strength of SAC-16 mixture was analyzed by uniaxial penetration experiment. The results show that various morphological parameters of coarse aggregate have different degrees of influence on the shear strength of the mixture, and the flatness ratio has the greatest influence on the shear strength, and the content of flat particles in the coarse aggregate must be controlled.