Wear resistance and skid resistance of 100 % reclaimed asphalt pavement

Abstract

This study aimed to evaluate the wear resistance and skid resistance of 100 % reclaimed asphalt pavement (RAP). Asphalt concrete with a normal maximum aggregate size of 13 mm (AC-13), similar gradation and aggregate composition to RAP, served as the control sample. A 1/3 scale accelerated loading abrasion equipment was employed to simulate the wear process. The surface texture and skid resistance of the asphalt mixtures were monitored using a laser scanner, British pendulum tribometer, tyre/pavement contact (TPC) print identification papers, and TPC finite element model (FEM) simulation. Key indicators such as mean deformation degree (MDD), mean texture depth (MTD), micro texture distribution (WL_TX), and wear degree (Structure similarity index measure based on texture depth, SSID) were calculated from texture data to track wear progression. Skid resistance was assessed using British pendulum number (BPN) and TPC areas. Results indicated that RAP exhibited greater deformation magnitudes and higher fluctuation amplitudes in texture compared to AC-13. Both SSID and BPN values of RAP deteriorated more severely, confirming consistent inter-material comparisons for wear and skid resistance. While RAP and AC-13 exhibited comparable initial skid resistance, RAP demonstrated significantly inferior skid resistance, with both materials converging in the final stages of wear. The TPC area and BPN values of RAP followed similar trends, with a notable drop at 800,000 wear cycles, indicating a functional loss node. Improving the wear and skid resistance durability of RAP requires an optimized coarse aggregate composition.