多尺度下沥青路面高温变形与裂纹协同发展机理研究及仿真分析

项目名称： 多尺度下沥青路面高温变形与裂纹协同发展机理研究及仿真分析

项目编号： No.51308303

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 李强

作者单位： 南京林业大学

项目金额： 25万元

中文摘要： 工程实践中发现在高温条件下沥青路面的破坏机理十分复杂，永久变形与裂纹往往会共生且相互影响，目前对两者的协同发展行为缺乏研究。本课题根据路面结构的实际应力状态、轴载谱以及温度场，结合室内保温试验和有限元方法，在室内试验中对沥青路面应力场和温度场进行耦合模拟，建立基于沥青路面实际工作状态的整体结构高温变形试验方法。进行室内试验，采用X射线断层扫描（CT）和数字图像处理技术对高温变形过程中沥青路面细观结构演变行为进行分析。通过宏观破坏和细观结构结合分析，研究沥青路面高温变形与裂纹协同发展机理，确定压密变形、剪切流动变形以及裂纹的组成与分布特征，揭示不同沥青层位的主要破坏机理和变形贡献率。基于有限元方法和多尺度关联技术，建立非线性粘弹塑性损伤模型，对动载作用下沥青路面高温变形与裂纹协同发展行为进行数值模拟，为深刻地认知沥青路面高温病害以及进行抗车辙路面结构和材料组合设计提供理论依据。

中文关键词： 沥青路面；永久变形；裂缝；细观结构；多尺度

英文摘要： It is shown in field that the failure mechanism of asphalt pavements at high temperatures is quite complex. Permanent deformation and cracking occur simultaneously. The synergetic development needs to be further studied. In this study, the stress and temperature fields in asphalt pavements are coupledly simulated in laboratory tests. A permanent deformation test with full-depth asphalt layers based on in-situ conditions of pavements is developed. The specimen size, loading head size, loading pattern and temperature gradient used in the test are determined according to actual stress state, axle load spectrum and temperature field in pavements using laboratory heating test and finite element method. After performing this test, the evolution of mesostructure for asphalt pavement in the process of deformation is analyzed using CT scanning and digital image process techniques. In combination of macroscopic damage and mesostructure, the synergetic development behavior of deformation and cracking in asphalt pavements at high temperatures is studied. The composition and distribution of densification, shear flow and cracking are determined. The failure mechanism and contribution to deformation for different asphalt layers are also discovered. The nonlinear visco-elastic-plastic damage model is developed for asphalt pavem

英文关键词： Asphalt pavement；Permanent deformation；Crack；Mesostructure；Multiscale