Study On The Influence Factors And Application Of SMA Asphalt Pavement Skid Resistance In South China

As a major economic province in China,Guangdong Province has a large traffic volume and a high percentage of heavy loads.Under the conditions of high temperature and rainy weather and concentrated distribution in the southern region,the shortcomings of traditional AC graded asphalt pavement were exposed,such as,the emergence of early diseases including water damage,rutting,cracks and faster anti-slip performance attenuation.Due to the larger thickness of the oil film and the addition of fibers,the dense-frame type SMA asphalt has better high-temperature stability,low-temperature crack resistance,durability and rough wear-resistance than the traditional suspension-density AC asphalt,which is a feasible solution with insufficient AC performance.However,SMA has high requirements for high-quality coarse aggregates,gradation design,mixing,paving,rolling and other construction processes.Once the construction process is not well controlled,problems such as oil bleeding and rapid reduction of initial anti-slip performance are prone to occur.Firstly,the survey results of representative quarries in various provinces show that the current high-quality stone is relatively scarce and the high-quality basalt and diabase in the local areas of each province are the main sources of the new highway upper layer.According to the planning map of the highway in Guangdong Province,the rock distribution along the highway and a large number of investigation and test data of stone processing factories,the distribution of rock and mineral resources in Guangdong Province was summarized,which will provide guidance for the selection of aggregates for highway construction and maintenance in the future.Then,according to the CAVF(Coarse Aggregate Voild Filling)method,coarse,medium and fine SMA-13 were designed,and the digital image technology was used to process the sliced image of the mixture sample.Based on the OTSU method,the coarse aggregate particles were extracted from the slice image of the asphalt,and the void ratio of the coarse aggregate skeleton calculated by the digital image method was proposed to evaluate the skeleton structure of the asphalt.With the interface evaluation technology of pressure film,and based on the laboratory rubbing test to simulate the anti-slip attenuation behavior of the firction course structure under the action of driving,the test shows that when the proportion of the coarse aggregate of the asphalt reaches a certain level,the anti-slip durability of the surface structure doesn’t change much,and appropriate combination of coarse aggregate and fine aggregate can help to improve the workability and construction uniformity of the mixture,or adding high-viscosity modified asphalt binder can also achieve a similar effect of skeleton embedded extrusion which can further improve the road Surface structure stability and anti-slip durability.Finally,based on the project,the impact of bitumen dosage,fiber type,fiber blending,rolling process,and bitumen type on the initial anti-skid performance of SMA-13 pavement was carried out.By paving different test sections,the structural depth and lateral force coefficient indexes were compared and analyzed according to the acceptance evaluation criteria,and the multi-factor sensitivity analysis method was used to calculate the sensitivity index of the influencing factors of anti-skid performance,which can provide guidance for material design and construction process optimization for improving the early anti-skid performance of SMA pavement.