基于ASTM标准的沥青路表横向离析评价

沥青路表既有纵向离析,也有横向离析,当前引入了ASTM标准仅对沥青路表纵向离析进行了分析,而摊铺机收斗处和横向接缝处出现的横向离析并未考虑。借鉴纵向离析评价法,提出了一种基于ASTM标准的沥青路表横向离析评价法,确定了横向检测道划分方式,明确了仅采用检测道间数据一致性统计量h来评价离析轻重情况。结合应用实例,得出:检测道8横向离析最为严重。研究表明,提出的横向离析评价方法能较为客观、准确地评价出路表横向离析,弥补了当前仅进行纵向离析评价存在的不足。

基于双侧窄角域摄影的沥青路表三维重构及构造特征分析

为满足无人驾驶车辆快速获取路表构造的需求,建立了基于双侧窄角域摄影的沥青路表三维重构方法.对室内压实混合料和室外路面进行表面三维重构,将平均构造深度计算值与铺砂法、环绕摄影的构造深度值进行比较,验证所建重构方法的正确性.建立了构造标准差、单位面积上峰数、峰高标准差等构造评价新指标,并应用于AC-13、SMA-13和OGFC-13构造分析中.结果表明:双侧窄角域摄影重构方法能快速获取路表的三维点云,重建三维构造;基于该方法的构造深度计算值与铺砂法实测、环绕摄影重构的构造深度值相当,适用于室内压实混合料和室外实际路面;所建立的构造评价指标能从构造分布特征、胎/路接触应力集中度等角度为无人驾驶车辆提供完整的路表构造信息.

Effects of asphalt pavement texture on hydroplaning threshold speed

Hydroplaning speed can be affected by pavement texture depth,thickness of water film,tire pressure and tread depth.In this study,to understand the influence of pavement texture on the hydroplaning speed,a new lab-scale apparatus has been designed and manufactured.The lack of proportion between linear movement of vehicle shaft and the wheel rotation was found to be a good index to determine hydroplaning threshold.A 5%drop in the ratio of wheel-to-axle rotation has been assumed as an index to determine hydroplaning threshold.Based on the measures,a simplified model was developed that is able to predict the hydroplaning speed depending on pavement's texture characteristics.The results indicated that a 77%increase in mean texture depth cause 9%increase in hydroplaning threshold speed.