Effect of combined polishing and freeze-thaw conditioning on the skid resistance of road surface

The aggregates used for the road surface layers, which are exposed to the continuous combined loading of traffic and weather conditions, are of central importance for the skid resistance. Currently the prediction of skid resistance is performed exclusively by means of polishing experiment, which simulates the loading conditions by traffic. In the scope of this paper plate specimens are produced with different aggregates and they are subjected to the combined loading of polishing and freeze-thaw. Based on the results of the skid resistance test and texture measurement, the impact from the freeze-thaw effect on the surface characteristics can be determined. In comparison to the aggregates of middle to coarse grains, those of fine to very fine grains are highly susceptible to the influence of freeze-thaw in terms of the long-term skid resistance. The skid resistance decreases shortly after freeze-thaw while the polishing afterwards can lead to either an increase or a decrease of the skid resistance, which mainly depends on the polishing duration and the initial skid resistance. From the results of simulated combination of traffic and weather conditions, it is recommended that, the freeze-thaw cycling be considered for investigation of skid resistance development of the road surface in later researches, especially when fine-grained mineral aggregates are applied in the road surface layer.