采用最大峰值角分布率评价沥青混合料的抗滑耐久性

为了评价沥青路面的抗滑耐久性,自主研发了两套实验设备:其一:沥青路面激光轮廓检测仪,其二:加速加载搓揉试验机。结合这两套实验设备,采集0,2,4,6,8 h搓揉试验的车辙板表面轮廓并生成轮廓曲线,统计路表轮廓夹角分布规律,提出最大峰值角分布率来表征沥青路面的抗滑耐久性。结果表明,随着搓揉时间的增加,钝角变多,即最大峰值角分布率逐渐增大,这说明路表轮廓棱角变平,抗滑性能下降,GAC-13车辙板的抗滑性能衰减程度低于AC-13,并且GAC-13车辙板的初始及最终抗滑性能均优于AC-13。并将最大峰值角分布率与构造深度(MTD)及摆值(BPN)做相关性分析,结果显示相关性显著,因此取最大峰值角分布率来表征路面抗滑耐久性是合理准确的。在室内结合加速加载搓揉试验机,激光轮廓检测仪,形成一套采用最大峰值角分布率来评价沥青混合料的抗滑耐久性的方法,弥补现阶段沥青混合料设计阶段没有验证其抗滑耐久性的缺陷。

Evaluate the skid durability of asphalt mixture by using the maximum peak angular distribution rate

A new experimental approach for evaluating the skid resistance durability of asphalt mixtures during the mix design procedures is proposed with the utilization of two auto-manufactured testing apparatus (Laser contour detector and accelerate loaded rub testing machine). Two kinds of asphalt mixtures with different gradation, such as GAC-13 and AC-13, for maximum aggregate size of 13mm are utilized in this study. Rutting specimens manufactured with the above asphalt mixtures respectively are firstly loaded with the accelerate loaded kneading machine, and the surface skid characteristics, likewise maximum peak angular distribution rate, Mean Texture Depth (MTD), and British Pendulum Number (BPN) of rutting specimen after loaded for 0, 2, 4, 6 and 8 hours are followed captured. Results illustrate that the maximum peak angular distribution rate increases with the loaded time and the increasing trend of asphalt mixtures with gradation GAC-13 is more gently than the asphalt mixtures with gradation AC-13. In other words, the skid resistance durability of asphalt mixtures with gradation GAC-13 is better than that of AC-13. As anther illustration, the maximum peak angular distribution rate shows a better linear relationship with the MTD and BPN. The maximum peak angular distribution rate is a reasonable indicator for assessing the skid resistance of asphalt mixtures. Combining the accelerated loading rub testing machine and the laser contour detector in the lab, the method to evaluate the skid durability by using the maximum peak angular distribution rate is formed, which can make up the shortage that the skid durability is not verified in the design period of bituminous mixture currently.