Impact of aggregate types, dosages, and binder levels on pavement early bonding and skid resistance: An enhanced laboratory wear analysis

As road traffic safety concerns continue to grow, the ultra-thin friction layer has emerged as a crucial safety feature that can significantly enhance pavement skid resistance and reduce safety risks. However, challenges such as early particle loss and the rapid decay of skid resistance have hindered the widespread adoption of ultra-thin friction layer technology. Furthermore, effective methods for assessing the bonding and skid resistance performance of these pavements have been lacking. To address these challenges, this study investigates the impact of aggregate types, dosages, and binder levels on pavement early bonding and skid resistance, using an enhanced laboratory wear analysis method. Ten different aggregates were analyzed, and the study explored the effects of various aggregate types and dosages, as well as binder levels, on pavement performance. Compositional and surface morphological differences among the aggregates were examined using X-ray fluorescence spectroscopy (XRF) and scanning electron microscopy (SEM). Enhanced wear tests, along with the Aggregate Natural Loss Test, British Pendulum Tester (BPT), and Sand Volumetric Method, were employed to assess the bonding and skid resistance performance of different aggregate-binder combinations. The findings reveal that the enhanced wear test effectively captures the initial bonding and skid resistance performance across various aggregate and binder combinations. The study also identifies key factors influencing the aggregate natural loss rate (ALN) and wear loss rate (ALW), showing significant correlations with aggregate quantities, types, surface micro-textures, and technical properties. Early wear had minimal impact on pavement friction, but the Mean Texture Depth (MTD) consistently decreased with increased wear cycles. At a binder quantity of 1.0 kg/m², an ultra-thin friction layer made with silicon carbide (aggregate #7) showed the best cost-effectiveness, while the use of slag (aggregate #10) resulted in the lowest cost-effectiveness. This study provides novel insights into the combined effects of aggregate characteristics and binder levels on the performance of ultra-thin friction layers, offering valuable guidance for optimizing pavement design to improve early bonding and long-term skid resistance.