多场耦合下盐渍化沥青道路结构损伤行为多尺度感知与表达

There is wide saline soil in our country. Combined with the artificial factors, asphalt road is more and more significantly eroded by salinization. Thus, the use of performance and durability of road was seriously affected. In this project, the field investigation，indoor and field test, and the theoretical analysis and numerical simulation methods are adopted based on the domestic and foreign research status. Starting with the expression of water and salt migration and diffusion regularity, water and salt distribution features of the pavement structure and deformation characteristics of subgrade structure is acquired. And then, industrial CT and SEM microstructure test are used to analyze pavement materials microstructure damage and to propose evolution and behavior equation of evolution of interlayer contact state, which is affected by the water, salt, and temperature. In full consideration material performance degradation, interlayer contact state evolution pattern, local deformation and different load conditions, fine 3 d finite element model was built to carry out research of numerical simulation of road structure. The mechanical behavior and disease mechanism of asphalt pavement corroded by salt water is comprehensively analysis combined with the indoor accelerated pavement testing. It is finally realized that multi-scale structural damage mechanism is detected based on road material microstructure evolution behavior and macroscopic structural mechanics behavior of salt water erosion and structural damage behavior is expressed based on water and salt erosion - interlayer contact state - material damage three factors. It will give powerful supporting for asphalt road construction and the structure performance evaluation in saline soil area.

我国盐渍土分布广泛，加之人为因素影响，沥青道路受盐渍化侵蚀愈来愈显著，严重影响了道路的使用性能和耐久性。本课题拟在国内外研究的基础上，采用现场调研、室内外试验、理论分析和数值模拟等手段，从水盐迁移和扩散规律的表征入手，获得路面结构的水盐分布特征及路基结构变形特性。进而通过工业CT和电镜微观结构扫描试验，分析受水、盐、温度影响的路面材料微观结构损伤，提出层间接触状态演化的行为方程；充分考虑材料性能衰变、层间接触状态演化、局部变形以及不同荷载作用模式等综合因素，构建精细化三维有限元模型，展开道路结构力学响应的数值模拟研究；结合室内加速加载试验，全面解析受水盐侵蚀的沥青路面力学行为及病害机理。最终实现考虑微观结构演化行为和宏观结构力学行为的多尺度结构损伤机理感知，以及基于水盐侵蚀-层间接触状态-材料性能劣化的三因素结构损伤行为表达。预期成果为盐渍土地区沥青道路建设和结构性能评价提供技术支撑。

我国盐渍土分布广泛，且受人为因素与环境因素影响，沥青道路盐渍化加剧，严重影响了道路的使用性能和耐久性。本课题在国内外研究的基础上，采用现场调研、室内外试验、理论分析和数值模拟等手段，从水盐迁移和扩散规律的表征入手，获得路面结构的水盐分布特征及路基结构变形特性。进而通过室内试验与数值模拟 ，分析受水、盐、温度影响的道路不协调变形及材料微观损伤机理，并建立基于材料物性指标的两种模型参数的预估公式；分析盐渍化对沥青道路层间接触状态的影响，明确沥青-集料间粘结、剥落作用以及基-面层材料对水盐吸附能力对层间接触状态影响范围，提出以层间抗剪强度和层间剪切模量作为层间接触状态的评价指标；考虑水盐侵蚀、层间接触状态、材料性能劣化三因素，采用数值模拟、基于水盐侵蚀的层间接触试验、剪切试验、复合小梁室内试验，全面解析受水盐侵蚀的沥青路面力学行为及病害机理。最终实现考虑微观结构演化行为和宏观结构力学行为的多尺度结构损伤机理感知，全面评价盐渍化地区沥青路面在荷载和非荷载因素共同作用下的实际工作性能与状态，对于我国盐渍化地区道路的结构设计和评价路面结构的补充具有实际应用意义和重要价值。