Evaluation of Polishing Behavior of Fine Aggregates Using an Accelerated Polishing Machine with Real Tires

The long-term durability of both coarse and fine aggregate significantly affects the mechanical performance of asphalt pavements. Extensive investigations of aggregate durability have been conducted on coarse aggregate in recent years, but never before has there been more emphasis on research to evaluate fine aggregates and the change of morphological characteristics. This study evaluated and compared the durability of different types of fine aggregate by means of a polishing test. Ten different types of aggregate were selected to ensure a sufficient variation of shape and polishing behavior. An innovative method was applied to create a slab to test the polishing behavior of fine aggregate while avoiding the influence of coarse aggregate and binders. The self-developed Harbin accelerated polishing machine (HAPM) was used to simulate the polishing process with real tires under controlled testing temperatures. The durability of fine aggregate can be well described by the polishing behavior by combining the fine aggregate polishing susceptibility (FAPS) and the final British pendulum number (BPN) value. The final BPN value represents the long-term polishing resistance, while the FAPS is a signal for the rate at which the pavement skid resistance decreases. A new type of fine aggregate composed of ceramic is evaluated and validated to be a potential material to ensure the long-term durability of pavements based on the excellent polishing resistance.