Research On Optimizing The Skid Resistance Of SMA Pavement Based On Aggregates’ Discrepant Abrasion Principle

On account of the superior performance of SMA pavement, recent years SMA pavement has been quite widely used in China. The anti-slide performance of some SMA pavement is much well at the initial stage, but with the repeated action of vehicle load, the anti-slide index of SMA pavement decays faster than other performance index; on the other hand, SMA pavement has a high requirement for the aggregate properties. For some regions lacking of high quality aggregate, large scale transit of high quality aggregate is needed when building SMA pavement, which greatly increases the construction cost. In view of this, the paper optimized the skid resistance performance of SMA pavement based on aggregates’ discrepant abrasion principle, which is significant for improving the skid resistance durability of SMA pavement. At the same time, it is of guiding significance for regions lacking of high quality aggregate to save the cost of SMA pavement construction.Firstly, the basic properties of aggregate were measured. 4 kinds of coarse aggregate and 2 kinds of fine aggregate were selected to measure the index such like mineral composition, mechanics index and surface texture. The performance differences among different kinds of aggregates were compared and the reasons were analyzed, which provided the basis for the selection of aggregate for SMA mixture based on the aggregates’ discrepant abrasion principle.Secondly, the mix design of SMA mixture were finished. Literature about optimizing the performance of SMA pavement was collected and analyzed and 10 groups of aggregate gradation were selected; 3 groups of aggregate gradation were selected through comparing the performance of all the 10 groups of aggregate gradation. By comparing the high temperature performance, water stability and skid resistance performance of the 3 groups of aggregate gradation mixture, the 1 group of gradation with the best performance was selected to carry out the following experiments.Finally, 4 kinds of coarse aggregate were mixed in 3 ways based on aggregates’ discrepant abrasion principle for mix design, and 13 kinds of SMA mixture were obtained. Conducted the longtime accelerated polishing experiment of the 13 kinds of SMA mixture by using the wheel polishing machine. Analyzed the data of polishing experiment under different loading times with asymptotic model. Studied the longtime skid resistance performance of SMA mixture with different aggregate mixing methods.In addition, the relation was researched with grey relational analysis among the stable BPN of SMA mixture and the performance of aggregate. It was found that the aggregate polishing value has the greatest influence on the stable BPN of SMA mixture, which provided basis for the selection of aggregate for SMA mixture.