【作者】 张涓；

【导师】 刘朝晖； 钱国平；

【作者基本信息】 长沙理工大学 ， 道路与铁道工程， 2008， 硕士

【摘要】 沥青路面是我国高等级公路路面结构的主要形式之一。随着我国交通运输的快速发展、重车和轮压的增大,沥青路面早期破坏现象愈来愈普遍,重载已成为影响路面使用性能和缩短路面使用寿命的重要因素之一。大交通量和超载严重的车辆,导致路面结构层内产生较高的水平剪应力,加上在高温环境下沥青混合料的抗剪能力下降,使沥青路面出现了严重的车辙的情况,尤其在渠化交通处更为明显。因此研究沥青混合料的高温抗剪性能就显得十分迫切。本文从半刚性基层沥青路面结构和材料性能两个方面入手,研究重载交通沥青路面高温抗剪性能。结构力学分析方面,采用BISAR程序,对重载作用下路面结构进行力学分析,计算不同的荷载作用下的各结构层层内的最大剪应力,得到结构剪应力随深度的分布规律,确定最大剪应力出现的层位;分析沥青面层厚度、不同轴载和模量等因素对面层内部剪应力的影响,得出沥青路面面层剪应力峰值变化规律和影响因素。材料性能方面,对影响沥青混合料抗剪强度的主要因素进行分析,评价了沥青混合料抗变形能力的试验方法。采用三轴重复荷载蠕变试验、单轴贯入试验和车辙试验方法对硬质沥青(A-30)、普通重交沥青(A-70)、改性沥青的混合料的抗剪性能进行了全面的对比研究,为硬质沥青在我国道路中的应用研究提供参考。研究发现,采用高模量沥青混凝土的路面结构,在力学指标上具有明显的优势,是提高结构抗剪性能的有效措施;为适应高温重载条件下的高压轮胎,面层尤其是上面层和中面层要采用高强度、高模量的材料;提高沥青混合料抗剪强度,在高剪应力区域采用硬沥青或者改性沥青是非常有效的。更多还原

【Abstract】 Asphalt pavement is one of the primary structures for main roads in China.Along with the appearing and forming of the heavy-loaded traffic in recent years,the premature failure of asphalt pavements is becoming more and more widespread.Consequently,over loading has become one of the key factors which influence the pavement performance and shorten the pavement life. The serious traffic and over loading of vehicles result in higher shear stress in the pavement structure. The asphalt mixture shear capability is decreased under high temperature environment, thus rutting is serious, particularly at the channel traffic. So studying the shear strength of asphalt mixture under high-temperature seems to be urgent.The high-temperature shear studying of heavy-loaded asphalt pavement has been conducted on two aspects about semi-rigid asphalt pavement structure and material performance in this paper. On the one aspect, analyzing heavy-duty pavement structure by using BISAR, calculating maximum shearing stress of the structure layers under different load function, getting the shearing stress of asphalt pavement structure interior along with depth change rule and determining the position with the maximum shear. The paper analyzes the influence on shear stress by the factors of asphalt layer thickness, different loading and modulus, the change of shear stress peak of asphalt pavement structure interior and influencing factor is attained. On the other aspect, the main factors of influencing asphalt mixture shear strength are analyzed, evaluating the test methods of the ability to reduce deformation of the asphalt mixture. Using triaxial repeated load creep test, uniaxial penetration test and rutting test, the author analyzes the shearing properties between high viscosity base asphalt mixture,asphalt mixture for paving heavy traffic road and SBS modified asphalt mixture by general comparative study,for providing reference about application and research of high viscosity base asphalt in our road.Research found that using high modulus of asphalt concrete pavement structure, mechanical indicators has obvious advantages. It’s an effective measure to improve the structure of the shear. For the adjustment to high pressure tires under high temperature and heavy loading, the high-intensity and high modulus of the material should be using on asphalt pavement ,especially surface layer and middle layer. Improve shear strength of asphalt mixture in the high shear stress region by high viscosity base asphalt or modified asphalt is very effective.更多还原