温度和荷载对沥青铺装层车辙形成的影响

采用ABAQUS在不同温度和荷载条件下对沥青铺装层进行力学分析,揭示沥青铺装层的车辙形成机理。结果表明:温度越高,上面层同一深度处最大应力越大;不同荷载作用时上面层受力趋势基本相同,但荷载越大,上面层沥青混合料应力越大。上面层、中面层和下面层荷载作用区域受压应力控制,水稳基层荷载作用区域则受拉应力控制。     

Probabilistic parametric approach for rutting evaluation: application to hot and warm asphalt

This paper deals with a stochastic approach to evaluate the rut depth of hot and warm bituminous mixtures. First, the rutting performance of both mixtures using the French rutting tester device was evaluated. Given the random uncertainties derived from the numerous experimental measurements of the rut depth, statistical information was collected. Accordingly, the entropy maximum principle was used here to define adequate probability density function of the rut. Confidence regions with a high probability of 99% were determined for the estimation of the rut depth. In addition, comparison of mechanical and rheological results is performed with aged bitumen recovered from reclaimed asphalt and virgin bitumen to analyse the effect of ageing on bitumen viscoelastic properties. The experimental characterisation of the different binders based on rheological and conventional tests showed stiffening and hardening effects due to bitumen ageing.     

沥青混合料动态蠕变模量与动稳定度的关系

研究了分别基于AC13和AC25优化出的9组级配、SBS改性中海70#沥青和中海70#沥青两种结合料、花岗岩和石灰岩两种集料以及50,70 mm两种车辙试件厚度等条件下的沥青混合料动稳定度(DS)与车辙模量(E_(DS)),E_(DS)与动态蠕变劲度模量(S_(dy)),S_(dy)与DS这三者的关系.结果表明,不同沥青混合料的S_(dy)与采用厚度匹配的车辙试件DS之间存在良好的相关性.因此可以将DS转换为S_(dy),并用其作为沥青路面结构设计的参数.     

Comparisons with high viscosity additive effects on base and modified asphalt

In this research, three types of high viscosity additives with different volumes were added to both 70# base asphalt and SBS modified asphalt, the dynamic viscosity and high temperature performance tests were conducted. The results show that with the same volume and type of the additive, SBS modified asphalt has a much higher dynamic viscosity and high temperature grade than those of the base asphalt. When the volume of each additive type increases from 0% to 12%, the dynamic viscosity would increase in a different trend, which could be described as three stages with different increasing speeds, and the variability and the demarcation point of the adjacent two stages depend on the asphalt modification, additive type and the volume. With regard to the high temperature grade, it was found that the effect of different additive types on high temperature performance should be separated from asphalt modification.     

城市道路交叉口沥青加铺层路面结构分析与设计

结合S120大修工程实际,总结和分析了交叉口沥青路面加铺层车辙、裂缝等病害及其产生原因,同时针对交叉口的运行特点对路面结构进行力学分析;确定旧水泥混凝土路面加铺沥青路面结构的最大剪应力区和抗车辙区,为交叉口路面结构和材料的抗车辙、抗裂设计提供依据.根据力学计算分析结果,提出几点适合交叉口的路面结构组合和材料选择的建议.     

硬质沥青及其混合料高温性能试验研究

本文对硬质沥青(A-30)和目前沥青路面常用的重交沥青(A-70)进行了DSR试验,对比分析了30号硬质沥青的高温性能;对四种沥青混合料进行单轴蠕变试验和车辙试验,分析了30号硬质沥青混合料的高温性能.试验结果表明:硬质沥青混合料可提高路面结构的高温稳定性,适用于基层铺装.     

大跨径钢桥面铺装设计理论与方法研究

结合南京长江第二大桥、舟山桃夭门大桥、润扬长江公路大桥和杭州湾大桥等大型桥梁桥面铺装的研究与设计 ,对大跨径钢桥面铺装设计理论与方法 ,包括铺装材料与结构、钢桥面铺装体系受力特性、疲劳特性、热塑性沥青混合料铺装车辙、设计指标、轴载换算方法、设计方法等关键技术进行系统的分析与研究 ,研究成果已在多座大跨径钢箱梁桥面铺装设计和铺装工程中应用     

沥青路面全厚度车辙影响因素的正交试验研究

考虑温度、荷载和厚度三个因素,并选取相应的因素水平,对武汉市三环线武黄高速公路共线段采用的沥青加铺结构层进行全厚度车辙试验。利用正交试验分析方法得出对车辙试验中动稳定度DS、车辙深度RD影响程度为:荷载>温度>厚度;当上面层、中面层采用改性沥青时,可适当减小整个沥青结构层的厚度;进行车辙试验时,应同时考虑DS与RD两个指标。     

朱圩子立交桥面铺装病害分析及养护技术研究

对朱圩予互通立交原桥面铺装病害类型及成因进行调查分析,提出了相应的养护方案并从施工难易程度、可操作性等各方面进行对比分析,确定可行方案及相关技术要求,同时分析了沥青混合料添加抗车辙剂前后的压实特性,通过汉堡轮辙试验对其高温稳定性及水稳定性能进行对比验证。     

沥青混合料抗剪性能研究综述

总结并评价了沥青混合料抗剪试验方法、抗剪机理及抗剪设计研究现状,对9种剪切试验方法的分析和评价有助于设计、施工和科研人员正确选用这些试验方法。混合料剪切强度由沥青胶泥的性质、集料和沥青界面的剪切强度和集料之间的嵌挤情况共同决定,为提高混合料抗剪性能指出了方向。抗剪设计在应用于工程前尚需深入研究容许剪应力法中相关系数的确定、基于抗剪性能的车辙预估模型的标定等问题。