Numerical simulation of the compaction process and the layer bonding with the multiscale modeling

重型运输基础设施需要最佳的材料组成，精确的施工工艺和尽可能最好的压实，以确保足够的耐久性。在子项目2的第一个申请期的范围内，沥青的微力学有限元公式被开发出来，以描述材料成分和各自材料成分之间的相互作用。在施工和压实过程中对机制的基本理解尚未确定。沥青层之间的粘合是沥青路面耐久性的另一个先决条件。在第一个申请阶段，子项目1和子项目4基于宏观、现象学公式发展了所需的理论和实验基础。由于材料的各个组成部分之间的粘附、摩擦和联锁而产生的键合的潜在机制应在微机械方法的应用下进行研究。第一个应用阶段的结果提供了所有必要的先决条件，即关于沥青压实和层粘合的潜在机制的基本知识，目前还没有，可以在微观结构尺度上确定。特别地，这是指子项目2和子项目3的各种沥青的微观结构分析结果。生成的数据是微力学模型的基础。这些模型在子项目2中用于确定沥青微观结构与抗疲劳和抗变形的关系。子项目4、子项目3建立实验基地。将微观模型整合到子项1的宏观连续力学有限元模型中，以便对整个路面上部结构进行分析。在考虑地表特性和底盘参数的情况下，借助子项1、3和5的方法确定交通诱导荷载。利用第一次应用期的结果，可以精确计算沥青路面和交通接缝中的机械载荷。此时，加载过程和损伤过程之间的关系可以用微力学过程来描述。在第二个应用阶段的范围内，将在子项目2中开发微观和细观力学模型，以加强对施工和压实过程中潜在过程的理解，最终通过精确影响沥青微观结构和未来沥青层之间的粘合来优化这些过程。第二个应用阶段的另一个目标是为耦合模型的大规模验证建立实验基础，并将不确定的材料参数从微观尺度转移到宏观尺度。

Heavy duty transportation infrastructure requires optimal material compositions, precise construction processes and the best possible compaction to ensure sufficient durability. In the scope of the first application period for subproject 2 micro mechanical finite elements formulations for asphalt were developed to describe the material composition and the interactions between the respective material components. A fundamental understanding of mechanisms during construction and compaction processes has yet to be determined.The bonding between layers in asphalts is another prerequisite for the durability of asphalt pavements. In the first application period subprojects 1 and 4 developed the required theoretical and experimental fundamentals based on macroscopic, phenomenological formulations. The underlying mechanism of bonding due to adhesion, friction and interlocking between respective components of the material shall be investigated under application of micromechanical approaches.The results from the first application period offer all necessary prerequisites, that fundamental knowledge about the underlying mechanisms of asphalt compaction and layer bonding, that is not currently available, can be determined on a microstructure scale. In particular, this refers to results on the analysis of the microstructure of various asphalts from subprojects 2 and 3. The generated data represents the basis for micromechanical models. These models were used in subproject 2 to determine the relation between the microstructure of asphalt and the resistance against fatigue and deformation. The experimental base was established in subprojects 4 and 3. The micro-model was integrated into the macroscopic continuum mechanical FE-model of subproject 1 to allow for the analysis of entire pavement superstructures. Traffic induced loading was determined with the aid of approaches from subprojects 1, 3 and 5 under consideration of surface characteristics and chassis parameters.Precise calculations of mechanical loading in asphalt pavements and joints due to traffic can be conducted with the results from the first application period. At this point, the relationship between loading and damaging processes can be described with micromechanical processes. In the scope of the second application phase, micro- and meso-mechanical models are to be developed in subproject 2 to enhance the understanding of underlying processes during construction and compaction to ultimately allow for an optimisation of these processes by precisely influencing the asphalt microstructure and the bonding between asphalt layers in the future. Another objective in the second application phase is establishing an experimental base for a large-scale validation of the coupled models as well as transferring the uncertain material parameters from the micro into the macro scale.