沥青路面材料多尺度域力学行为及跨越机制

The influence of micro and meso level characteristics on its macro mechanical behavior was not considered into traditional pavement mechanical analysis which is based on classic continuum medium concept. As a result, the multi-scale mechanical behavior and trans-scale mechanism will be studied. At first, based on modern microcosmic testing technology and related viscoelastic mechanics and interface mechanics theories, the microcosmic characteristics, mechanical model and its parameters testing method of the interface between aggregate and asphalt/mastic are investigated. Then, Computer Tomography(CT) scanning and image processing technology are used to obtain meso-level distribution. non-uniform distribution and homogenization method in the meso-level of ashalt mixture based on composite material mesomechanics are researched here. The mechnical behavior at the meso-level is to be analyzed. What's more, the multi-scale integrated model will be established considering anisotropy and damage followed by the development of UMAT subroutine based on ABAQUS software. The effect of model parameters on the mechanical behavior is also disscussed. Finally, through the Finite Element Method(FEM) numerical simulation about the tire-pavement contact and non-uniform moving loading, the mechanical behavior at the macro-level and trans-scale mechanism of asphalt material are to be studied. .This research will identify the transfering and transforming relationship among different scales, which will provide basis for the performance prediction and optimum design of asphalt material. It will also support the research about damge mechanism of pavement material.the proposed research may promote the development of pavement mechanics and material science.

针对传统连续介质路面力学分析中未考虑沥青材料微细观特性影响的问题，拟定研究沥青混合料多尺度域力学行为及跨越机制。首先，基于现代微观测试技术及粘弹力学、界面力学理论研究集料-沥青（沥青胶浆）界面特性、力学模型及参数测试方法；其次，采用CT断层扫描和图像处理技术获取混合料的细观组成，借助复合材料细观力学理论，研究其细观结构的非均匀分布特性和均匀化方法，分析混合料细观尺度下的力学行为；而后，建立考虑材料各向异性和损伤的多尺度域统一模型，开发UMAT 子程序，分析材料参数对其力学行为的影响；最后，基于胎-路接触分析和非均布移动荷载数值模拟，分析路面材料宏观尺度下的力学行为，探讨沥青材料尺度跨越机制。.本研究揭示了沥青材料多尺度域间力学行为的遗传变异关系，为优化设计混合料的组成和准确预估其路用性能提供了依据，也为研究路面材料的损伤机理奠定了基础。研究成果对于路面力学、材料学的发展有一定的推动作用。

沥青混合料材料组成的复杂形貌及空间随机分布导致其多尺度特性不可忽视。沥青混合料的宏观力学行为及损伤演变规律与其微、细观结构特性有着内在的关联性。为了指导实际工程应用问题，宏观尺度上沥青混合料的统计平均性质是沥青路面材料优选的主要指导方针。基于层状弹性理论的沥青路面结构设计方法满足连续介质力学理论所提出的材料均匀化假设。单一尺度下小尺寸构件力学性能评价及基于连续介质框架的理论计算分析无法从多尺度本质上解释沥青路面材料与结构的力学行为及损伤机制。因此，开展沥青路面材料多尺度域力学行为及各尺度间相互遗传变异关系的研究，有助于深入理解、分析及预估沥青混合料的力学性能。进而，从多尺度角度出发为沥青路面材料优化设计提供理论支撑及数据支持，为揭示沥青路面材料的损伤机理奠定基础。.为探究集料-沥青界面微观交互作用的影响规律，开展了集料-沥青体系分子模拟、集料粘附条件下界面区形貌观测及力学性能测试等研究。为定量评价沥青砂浆黏弹与低温特性，采用动态剪切流变试验与弯曲梁流变仪试验对比了沥青砂浆的性能差异。为系统描述沥青混合料细观结构分布规律，基于工业CT三维实体虚拟化重构技术描述粗集料、空隙及骨架等组分的细观结构分布规律。为创建沥青路面材料虚拟化试验设计平台，基于细观单元等效模型、多尺度统一模型及胎-路交互作用沥青路面结构模拟实现了沥青路面材料及结构设计的数字化试验方法。研究结果表明，集料-沥青界面微观交互作用对沥青力学性能的影响不可忽视，其影响依赖温度/频率、夹层厚度及加载模式。沥青砂浆力学性能评价有助于全面理解沥青混合料的多尺度特性，其性能与材料组成关系密切。沥青混合料细观结构参数的分布规律表征了材料的不均匀程度，其宏观性能与细观分布联系紧密。沥青路面材料多尺度统一模型是构建微-细-宏观尺度跨越的重要方法。