Auswirkung des Streumitteleinsatzes im Winterdienst auf die Griffigkeitsentwicklung der Asphaltoberflache

The use of gritting materials in the scope of winter services to help thaw ice and snow on the road surface is a widely spread method. To assess how the applied materiel, which remains on the road surface for a prolonged period affects the surface properties (such as micro-, macro texture and thus skid resistance) a number of tests will be conducted in the scope of this project. The asphalt samples are removed from a test track and thereafter polished by the Aachener Ravelling Tester under different conditions. The skid resistance is then measured according to the Whener! Schuize method. The results show that the skid resistance is influenced by gritting material and water on the road with regard to abrading the binder film as well as the polishing of the stones. In particular, when polishing under the absence of water, an adhesion of the rubber abrasion and the gritting material can be observed. This leads to the deposition of a thin film on the surface, leading to a decrease of the macro texture depth and thus a substantial reduction of the skid resistance. Compared to other gritting materials the use of de-icing salts removes the binder film quickly whilst leading to little changes of the macro-Texture depth of the aggregate. Therefore it represents an optimal opportunity to de-ice the road surface whilst maintaining the long term skid resistance and traffic safety.