Safety aspects of wet asphalt pavement surfaces through field and numerical modeling investigations

Good pavement macrotexture has a direct influence on vehicle safety during wet weather conditions by improving vehicle traction and braking ability. Apart from the macrotexture, several other factors, such as environmental, tire, and pavement-related characteristics, affect the wet friction. Most experimental studies had a limited scope of reusability as soon as there was a change in any of the other factors. In recent years, the development of powerful finite element tools has made it possible to simulate complex wet tire-pavement Interaction as close as possible to the actual field conditions. However, to the best of the authors' knowledge, none of the past analytical and numerical studies were able to include the actual pavement surface texture in their analysis. This paper describes an approach to study the effect of actual surface morphologies of asphalt pavements on the wet friction coefficient by using the finite element method. Asphalt surface morphologies representative of open-graded mix to close-graded mix were used in the finite element analysis. The finite element model was duly calibrated with the field investigations conducted with state-of-the-art field equipment. The extreme loss of wet friction, which ultimately led to the risk of hydroplaning, was also studied. The analyses were performed for two water film thicknesses, two tread patterns, and two tire slip ratios. The results from the current study can be ased as safety indicators of in-service asphalt pavements under wet and flooded conditions.