骨架约束作用对沥青磨耗层抗滑性能影响研究

以SMA沥青路面为例，基于体积法设计不同骨架磨耗层路面，并采用不同PG等级沥青胶结料进行骨架约束；采用室内搓揉试验模拟行车作用，用压力胶片技术进行胎路接触界面测试，开展骨架稳定性对沥青路面抗滑耐久性能影响研究。结果表明:相比摆式摩擦系数，采用接触应力分布集中度指标来表征路面有效抗滑性能更合理；搓揉试验表明，构造深度呈现单调递减衰减规律，级配骨架越强，对构造衰减有减缓作用；当骨架达一定程度，轮胎接触应力集中度增加并不明显，此时应关注混合料施工均匀性；采用PG82改性沥青路面构造深度、应力集中度的衰减速度低于PG76改性沥青路面，高性能沥青胶结料也能提供良好的骨架约束；路表整体构造衰减幅度约为轮胎接触区构造衰减幅度2～3倍，沥青混合料骨架稳定性同样有利于提升沥青路面抗滑性能耐久性。

Research on the Influence of Skeleton Constraint on the Skid-resistance Performance of Asphalt Wearing Layer

Taking SMA asphalt pavement as an example, the wear layer pavements with different skeleton have been designed based on volume method, and different PG grade asphalt binders have been used for skeleton restraint. Indoor rubbing test has been adopted to simulate driving action, and pressure film technology has been used to test the contact interface of tire and road. The influence of skeleton stability on skid resistance durability of asphalt pavement has been studied through all these steps. The results show that compared with the pendulum friction coefficient, it is more reasonable to use the concentration index of contact stress distribution to characterize the effective skid resistance of pavement. The rubbing test shows that the structure depth decreases monotonically, and the stronger the graded skeleton is, the slower the structure attenuation is. When the skeleton reaches a certain degree, the tire contact stress concentration does not increase obviously. In this case, attention should be paid to the construction uniformity of the mixture. The decay rate of structural depth and stress concentration of PG82 modified asphalt pavement is lower than that of PG76 modified asphalt pavement, and high-performance asphalt binder can also provide good skeleton constraint. The attenuation range of the overall structure of the road surface is about 2 ~ 3 times that of the structure in the tire contact area. The stability of the asphalt mixture skeleton is also conducive to improving the durability of the asphalt pavement skid resistance.