Influence of the gritting material applied during the winter services on the asphalt surface performance

Gritting materials such as de-icing agents are widely applied during the winter to help thawing ice and snow on road surfaces. They remain on the road for a certain period of time, which may affect the surface properties of the pavement, such as micro- and macro-texture and thus the skid resistance. In this paper, asphalt specimens are taken from a test track and subjected to a successively increasing polishing duration with various gritting materials as polishing agents with the Aachen Polishing Device. The skid resistance of these specimens is determined according to the Wehner/Schulze method. Results show that the skid resistance behavior was influenced by de-icing agent in terms of bitumen removal and polishing of the aggregates. In comparison with sand, de-icing salt has a positive effect on the skid resistance since it removes the bitumen film on the surface of the aggregates very fast while polishing the aggregates only to a minimal extent. It is therefore an optimal option for de-icing in winter services with regard to skid resistance and traffic safety.