effect of surface condition on the skid performance of the stone matrix asphalt

Road traffic accidents are one of the major issues that have been investigated by many researchers in transportation communities. one of the effective factors in reducing accidents is to improve the surface friction of the road pavements, which is often measured by the skid resistance. the presence of dust would reduce drivers’ field of view and also the skid resistance of the road surface, and thereby contributes many road accidents in these areas. in this research, the existing dust particles were collected from the surface of the roads. these fine dust with variable amounts were scattered as contaminants on the surface of asphalt samples and skid resistance was measured for hma and sma asphalt samples with different gradations and temperatures. the results showed that dust deposition on the pavement surface in three months causes pavement skid resistance in the two types of hma and sma asphalt mixtures, decreasing 9 to 16% in the dry state and 25 to 35% in the wet state. according to the obtained results, it is recommended to apply sma asphalt with a nominal size of 19 mm as a topeka layer in the areas that are exposed to fine dust, especially in conditions of high traffic and high ambient temperature.