Study On Effects Of Texture And Contaminants To Skid Resistance Of Asphant Pavements

Low skid resistance of road surfaces was one of the most important factors of potential traffic accidents. Skid resistance of asphalt pavements was mainly affected by pavement texture and mediums such as contaminants on road surfaces. So the study on effects of texture and contaminants on skid resistance of asphalt pavements was important.Characteristics of contact mode, the mechanism of friction between tire and road surfaces were analyzed to study effects of texture on skid resistance of asphalt pavements. Theories such as tire theory, theory of viscoelasticity, rubber friction theory and theory of hydrodynamic lubrication were applied to analyze the effects of macro-texture and micro-texture on skid resistance of dry, wet, high water asphalt pavements. Macro-texture and micro-texture had effects on skid resistance of dry, wet, high water asphalt pavements according to results of theory analyses.Texture and skid resistance should be tested to study their effects on skid resistance of asphalt pavements by experiment data. The test equipment based on laser distance measuring instrument was designed to test macro-texture of asphalt pavements. Micro-texture of asphalt pavements was tested by a stylus profile meter. A parameter system was built to describe texture characteristics of asphalt pavements correctly. Skid resistance asphalt pavements of was tested by improved British Pendulum Tester. Skid numbers-slip speed curve of asphalt pavements was tested by refitted MMW-1 universal abrasion testing machine. Skid numbers-load curve of asphalt pavements was also tested by refitted MMW-1 universal abrasion testing machine.Skid resistance of asphalt pavements decreased when slip speed between tire and road increased, according to skid numbers-slip speed curve. Skid resistance of asphalt pavements increased with load increasing according to skid numbers-load curve. When the relationship between texture parameters and skid resistance of asphalt pavements was analyzed, a conclusion could be obtained. Texture had some effects on skid resistance of asphalt pavements. The speed which skid resistance decreased at with slip speed, the speed which skid resistance increased at with load were both affected by texture of asphalt pavements. The experiment to study effects of contaminants on skid resistance of asphalt pavements was finished in the laboratory. Grit, sand, earth, lube oil and water were chosen as contaminants in this paper after analyzing the source of contaminants on real asphalt pavements. Contaminants had distinct negative effects on skid resistance of asphalt pavements. More densely contaminants distributed, the bigger negative effects contaminants had on skid resistance of asphalt pavements. Lube oil, contaminants with smaller grains such as sand and earth had long-term effects on skid resistance of asphalt pavements. Contaminants with bigger grain such as grit also had long-term effects on skid resistance of asphalt pavements when contaminants had dense distribution.The conclusions of this paper were useful for developing the skid resistance evaluation model based on texture parameters of asphalt pavements. The design, material choice and building of asphalt pavements with high skid resistance could find valuable information from the conclusions. The maintainer of highways could obtain suggestions for keeping skid resistance of asphalt pavements in this paper. Drivers could also find useful information for driving safely from this paper.