Influence of temperature on polishing behaviour of asphalt road surfaces

The skid resistance of road surfaces is crucial for traffic safety and varies due to the polishing effect of the traffic loads. Numerous prediction models for the skid resistance of asphalt pavements have been developed based on three standard polishing methods in accordance to regulations; Polished Stone Value (PSV), Micro-Deval (MD) and Wehner/Schulze machine (W/S). However, the aforementioned tests can only be carried out for given conditions such as under constant temperature. This does not fully represent real conditions on road surfaces, because asphalt exhibits a strongly temperature-dependent performance due to the viscosity of bitumen. In this paper, the polishing effect due to traffic and weathering was simulated with a self-developed device, the Harbin Accelerated Polishing Machine (HAPM). It is equipped with real tires and allows for the precise control of the testing temperature. The British pendulum number (BPN) and mean texture depth (MTD) were determined to describe skid resistance development during polishing process. Prediction models of skid resistance are created and the model parameters are calculated by means of a regression analysis. The influences of the temperature during polishing on the long-term evolution of skid resistance are studied.