Development of Design Procedure to Predict Asphalt Pavement Skid Resistance

Abstract

A laboratory design procedure was developed to evaluate the skid resistance of asphalt pavement with laboratory test results. For the development of the procedure, twelve typical asphalt wearing course mixtures with different combinations of aggregate sources and mix types were considered. The frictional performance of asphalt mixtures was evaluated with an accelerated polishing and testing procedure developed at the National Center for Asphalt Technology. The circular texture meter and the dynamic friction tester at various predetermined polishing cycles were used to evaluate the variations in surface texture and friction characteristics of asphalt testing slabs during accelerated polishing. The skid resistance of asphalt mixtures attributable to accelerated polishing was quantified with the international friction index number F60, which was computed with the friction numbers measured with the dynamic friction tester at 20 km/h and the obtained mean profile depth values. The analysis of F60 results led to the development of a set of friction prediction models and a laboratory friction-resistant mix design procedure. The developed procedure, which allows estimation of asphalt pavement skid resistance based on laboratory measured micro- and macrotexture results, is a useful tool for laboratory evaluation of a mixture's friction resistance. The procedure can also facilitate the use of locally available aggregates with lower skid resistance in a wearing course mix design and thereby produce both cost-effective and skid-resistant surface mixtures.