A Laboratory Investigation into the Polishing Behavior of Stone Matrix Asphalt with Different Lithology Types of Coarse Aggregates

Skid resistance durability is an important aspect of pavement durability. A full understanding of pavement polishing behavior is helpful to make improvement in material design to obtain better skid resistance durability. In this paper, the polishing behavior of stone matrix asphalt (SMA) with basalt, red sandstone, and limestone coarse aggregate, respectively, was investigated by a series of laboratory polishing tests. A British pendulum tester, a handheld three-dimensional (3D) laser scanner, and an interference principle based 3D optical microscope were employed to acquire the British pendulum number, 3D macrotexture, and 3D microtexture data, respectively. The test results show that the coarse aggregate lithology has significant influence on the wear behavior of macrotexture. No statistically significant microtexture degradation was recognized in the polishing tests for all the SMA mixtures with different lithology types of coarse aggregates. The skid resistance significantly changes due to polishing, and the skid resistance capability and degradation behavior are closely related to the coarse aggregate lithology. The selection of coarse aggregate lithology is important in SMA mixture design for achieving high polishing resistance. Among the three lithology types of coarse aggregates considered in this study, the basalt coarse aggregate can bring the best polishing resistance, followed by the red sandstone, which can bring similar performance to the basalt can do. The polishing resistance brought by limestone coarse aggregate is relatively low. The findings and conclusions enhance the understanding of the polishing behavior of SMA, which is helpful to improve the skid resistance of asphalt pavement in practice.