荷载与温度耦合作用下足尺路面颗粒迁移规律及车辙预估模型研究

With the development of heavy traffic and warming of global climate, rutting has already become the most serious diseases of asphalt pavement. The particle migration of asphalt mixture leads to rutting of asphalt pavement, under the coupling action of high temperature and vehicle load. So, discovery the particle migration regularity is the theoretical basis for solving rutting. Existing research mainly used the laboratory tests and continuum mechanics theory to study the mechanism and impacting factors of rutting, and develop predictive model from the perspective of phenomenology. All of these researches did not explore the mechanism of asphalt pavement rutting from the particle migration, leading to that the rutting problem have not been solved in better. In this project, accelerated pavement rutting test with ALF will be utilized to study the rutting of full-scale pavement under the coupling action of temperature and vehicle load, and image analysis technology to reconstruct the three-dimensional microstructure of the asphalt layer of the full-scale pavement, taken from before and after ALF loading. Then, the particle migration regularity of the asphalt layer of the full-scale pavement will be studied by the particle tracking technology. At last, mechanism of pavement rutting will be analyzed on the basis of particle migration pattern, and rutting predictive model is developed. The achievements will have important scientific implications for exploring the mechanisms of particle migration and rutting of asphalt pavement, and also be providing the new perspective for solving the rutting problem.

随着重载交通的发展和全球气候的变暖，车辙已成为沥青路面最严重的病害。沥青路面车辙是在高温与车辆耦合作用下沥青混合料颗粒发生迁移而产生的，揭示颗粒迁移规律是解决车辙问题的理论基础。已有研究主要采用室内试验和连续介质力学理论，从现象学角度研究车辙机理和影响因素并建立预估模型，并没能从颗粒迁移的本质去揭示沥青路面车辙产生的机理，因而车辙问题始终没能得到较好地解决。本项目拟采用ALF加速加载试验研究不同温度与荷载耦合作用下足尺沥青路面结构的车辙，采用图像分析技术构建ALF加载前后足尺路面沥青面层的三维细观结构，通过颗粒追踪技术研究足尺路面沥青面层的颗粒迁移规律，基于颗粒迁移规律分析路面车辙机理并构建车辙预估模型。研究成果对揭示沥青路面的颗粒迁移规律和车辙机理具有重要的科学意义，能为解决车辙问题提供新视角。

随着重载交通的发展和全球气候的变暖，车辙已成为沥青路面最严重的病害。路面车辙是在高温与车辆耦合作用下沥青混合料颗粒发生迁移而产生的，揭示颗粒迁移规律是解决沥青路面车辙问题的理论基础。已有研究主要采用室内试验手段和连续介质力学理论，从现象学角度研究沥青混合料车辙机理及其影响因素，并没能从颗粒迁移的本质上揭示沥青路面车辙产生的机理。本项目采用图像分析技术构建APA加载前后沥青面层的三维细观结构，通过颗粒追踪技术研究沥青面层的颗粒迁移规律（PPT），基于颗粒迁移规律分析路面车辙机理并构建车辙预估模型。对15种沥青面层进行了不同温度与轮压的APA加载试验，对APA加载0，2000，4000与8000次后的沥青面层进行X-ray CT断层扫描；基于MATLAB软件，创建了沥青面层CT图像数值化与三维细观结构重构方法，构建了APA加载0、2000、4000和8000次的沥青面层三维细观结构；基于Imaris构建了沥青面层的颗粒迁移仿真技术，基于PPT及沥青面层三维细观结构进行了颗粒迁移模拟，揭示了颗粒迁移的影响因素及其规律；基于PFC构建了沥青面层单轴贯入试验的颗粒流数值模拟方法，并据此进行级配优化提高沥青面层抗车辙性能25%左右；基于足尺沥青路面ALF加速加载车辙数据、颗粒流数值模拟等，建立了足尺沥青面层的车辙预估模型；开发了车辙非线性叠加与容许抗剪强度及动稳定度的软件系统（2套），提出了结构与材料一体化控制车辙的方法，构建了与轴载作用次数（使用寿命）、路面结构与层位、路面温度、行车速度相关联的混合料抗剪强度标准。研究成果对揭示路面的颗粒迁移规律和车辙机理具有重要的科学意义，提高沥青路面抗车辙性能25%左右，为工程实践提供了结构与材料一体化控制车辙的设计方法。