Extensive characterization of the material behavior of asphalt mixes with modified performance as a base for the multi-scale theoretical-numerical modeling

沥青混合料的材料性能对路面结构的耐久性有着重要的影响。对沥青混合料材料特性的了解构成了真实建模的基础，因此也是整个研究小组调查的基础。在第一个项目期间，主要关注的是对沥青(作为面层混合料的石膏沥青(SMA)和作为沥青基层混合料的沥青混凝土(AC T))及其组成的一般理解的发展。此外，在第一个项目期内制定了实验室测试和实验条件设计的程序。现在，在第二个项目期，将表征沥青在考虑沥青组成及其组成随路面结构各层应变和应力条件的变化而变化时的行为。在这里，将考虑不同的结合料和沥青砂浆的老化条件。从第一个项目期的研究中发现，沥青在不同的应力水平(拉压、应力值)下表现出不同的性能。因此，将研究沥青及其沥青组分在高循环荷载下的行为，以确定不同的性能范围。根据试验结果，将对第一个项目阶段开发的模型进行修改。这需要子项目4、子项目1和子项目2的迭代协作，以确定实验室试验的参数定义和加载条件。此外，该项目还将深入了解路面行为对单一不确定输入值的敏感性和不确定性，以及对影响路面耐久性的值的识别。为此，将研究单一不确定输入值的变化，如质量内结合料性能的变化、结合料含量、集料的粒度分布、沥青密度、层厚和层间结合对沥青混合料性能和整体路面结构的影响。在这种背景下，有必要建立一个合适的实验基础，以便更好地了解这种变异性对现实交通荷载下路面结构行为的影响。这些实验数据是项目合作伙伴ISD(次级项目1)和ISAC(次级项目2)对耦合系统进行非确定性(不确定)建模所必需的。

The material properties of asphalt mixtures have a significant influence on the durability of pavement structures. The understanding of the material behavior of asphalt mixes forms the base for a realistic modelling and therefore for the investigations of the entire research group.The main focus during the first project period was the development of the general understanding of the behavior of asphalt (stone mastic asphalt (SMA) as surface layer mix and an asphalt concrete (AC T) as asphalt base courser mix) and its components. In addition, the procedures for laboratory testing and the design of experimental conditions were developed within the first project period. Now, in the second project period, the behavior of asphalt under consideration of the variation of the asphalt composition and its components according to the strain and stress conditions in each layer of the pavement structure will be characterized. Here, different aging conditions of binders and asphalt mortar will be taken into account.From the research in the first project period it was found that asphalt shows different performance in in dependence on the stress level (tensile / compression, stress value). Hence, the behavior of asphalt and its asphalt components at high cyclic loading will be investigated in order to define different performance rages. Based on the test results the models developed in first project period will be modified. This requires an iterative collaboration of subproject 4 the subproject 1 with the subproject 2 for the parameter definition and identification of loading conditions for the laboratory tests.Furthermore, a profound understanding of the sensitivity and uncertainty of the pavement behavior with respect to the single uncertain input values as well as the identification of the values that influence the durability of pavements will be gained within this project. For that reason, the influence of ingle uncertain input values like the variation of binder properties within a quality, the binder content, the grain size distribution of the aggregates, the density of asphalt, the layer thickness and the layers bond on the performance of asphalt mixes and the overall pavement structure will be investigated. In this context, it is necessary create a suitable experimental basis for a better understanding of the impact of this variability on the behavior of the pavement structure under realistic traffic loading. These experimental data are required for the non-deterministic (uncertain) modelling of the coupled system undertaken by the project partners ISD (subproject 1) and ISAC (subproject 2).