超薄磨耗层抗滑性能的衰变规律及其影响因素

Skid Resistance Deterioration and Influencing Factors of Ultra-Thin Wear Layer

为了精确评价沥青超薄磨耗层开放交通后抗滑性能衰变过程、机理及影响因素,首先利用弧形模具及其配套的轮碾机来制备弧形超薄磨耗层试件;然后通过驱动轮式加速加载系统对4种级配类型和3个沥青胶结料等级的沥青超薄磨耗层试件进行加速加载试验;最后借助激光纹理扫描仪对一定轮载次数作用后的试件分别进行扫描。结合试验数据分别建立了基于S型函数的沥青超薄磨耗层宏观和微观构造深度衰变模型,以及基于灰色关联分析方法来分析各空隙率和沥青胶结料对抗滑性能的独立和耦合作用。试验研究结果显示:采用驱动轮式加速加载系统结合S型函数模型可以定量地评价和预测沥青超薄磨耗层性能的演变过程;空隙率影响超薄磨耗层宏观和微观构造深度的前期衰减速率,空隙率越大,则超薄磨耗层的宏观和微观构造深度的前期衰减速率越大;宏观构造深度的中后期衰减速率受沥青胶结料等级影响更大,沥青胶结料性能等级越高,则宏观构造深度的中后期衰减速率越慢;空隙率和沥青胶结料等级对超薄磨耗层微观构造深度中后期衰减速率的影响相当。因此,在进行超薄磨耗层抗滑性能设计时,选择大空隙率的开级配超薄磨耗层混合料级配对路面抗滑耐久性是有益的,而沥青胶结料的性能等级则可以根据交通量的大小合理选择。

To accurately evaluate the decay process,mechanism and influencing factors of anti-sliding performance of asphalt ultra-thin wear layer after opening to traffic,this study first used arc mold and its supporting wheel grinding mechanism to prepare arc-shaped ultra-thin wear layer specimens.Then,it carried out the accelerated loading test of asphalt ultra-thin wear layer specimens with four gradation types and three asphalt binder grades by driving wheel accelerated loading system.Finally,it scanned the specimens after a certain number of wheel loads by laser texture scanner.Combined with the test data,the macro and micro structure depth decay models of asphalt ultra-thin wear layer based on S-type function were established respectively,and the independent and coupling effects of each porosity and asphalt binder on skid resistance were analyzed based on grey correlation analysis.The experimental results show that the driving wheel accelerated loading system combined with the S-type function model can quantitatively evaluate and predict the evolution process of the performance of the asphalt ultra-thin wear layer.The porosity affects the early decay rate of the macro and micro structural depth of the ultra-thin wear layer.The larger the porosity,the greater the early decay rate of the macro and micro structural depth of the ultra-thin wear layer.The middle and late decay rate of macrostructure depth is more affected by the grade of asphalt binder.The higher the performance grade of asphalt binder,the slower the decay rate of macrostructure depth in the middle and late stages.Void ratio and asphalt binder grade have similar influence on the decay rate of the micro-structure depth of the ultra-thin wear layer in the middle and late stage.