Tribological approach to study polishing of road surface under traffic

The polishing phenomenon of road pavements under the vehicle traffic constitutes the main mechanism inherent to the loss of skid resistance over time. A better understanding of this phenomenon would allow an improvement of road safety. This study comprises a review of laboratory test and a model simulating the polishing of road surfaces. The laboratory test uses a polishing machine so called ‘Wehner–Schulze’ which can reproduce the evolution of the road texture from specimens taken directly from road or made in laboratory. The model is based on contact mechanics considerations and considers that the local polishing rate is controlled by the pressure distribution between the car tyre and the road surface. The model evaluates the pressure distribution by taking into account the surface roughness, the applied load and the mechanical properties of the bodies in contact. From the pressure distribution and a proposed wear law, the local roughness evolution of the surface pavement can be readily evaluated. The removal material is proportional to the contact pressure and to the aggregate properties used in roads mix design. The results show that the predicted road profile evolution is consistent with those given by experiments.