A 3D multi-phase meso-scale model is proposed to analyse the evolution of damage and transport properties in concrete. This model includes five phases: aggregates, mortar, voids, cracking and interfacial transition zones (ITZs) between aggregates and mortar. They are generated using measurable characteristics, such as shape, size and volume fraction of aggregates and voids. Mechanical part of the model is validated through comparing the predicted and experimental stress-strain curves and cracking patterns. Transport part of the model is validated by the comparison of predicted and experimental diffusivities of chloride ions in concrete. A new interface element type is also proposed to represent cracking in transport analysis which can simulate transport not only in normal directions but also in tangential directions. The effects of parameters relevant to aggregates, voids, ITZs and cracking patterns on the mechanical and transport responses of concrete are also analysed. The derived qualitative understanding of the relation between meso-structural features and macroscopic properties will help future advances in modelling and formulation of experimental programmes to improve the calibration and validation of meso-scale models. The proposed sequential mechanical-transport coupling model is applicable to a large class of composite materials with appropriate selection of phases and their properties.

提出了一种3D多相介观模型，用于分析混凝土损伤和运输特性的演变。该模型包括五个阶段：集料，砂浆，空隙，裂缝和集料与砂浆之间的界面过渡区（ITZ）。它们是使用可测量的特征生成的，例如聚集体和空隙的形状，大小和体积分数。通过比较预测的和实验的应力-应变曲线和裂纹模式来验证模型的机械部分。通过比较混凝土中氯离子的预测扩散率和实验扩散率，验证了模型的运输部分。还提出了一种新的界面元素类型来表示运输分析中的裂缝，该模型不仅可以模拟法向方向，而且可以模拟切线方向的运输。还分析了与集料，空隙，ITZ和裂纹模式有关的参数对混凝土的机械和运输响应的影响。对介观结构特征和宏观特性之间关系的定性认识将有助于实验程序的建模和制定方面的未来发展，以改善介观模型的校准和验证。所提出的顺序机械传输耦合模型适用于一大类的复合材料的同相和它们的特性的适当的选择。对介观结构特征和宏观特性之间关系的定性认识将有助于实验程序的建模和制定方面的未来发展，以改善介观模型的校准和验证。所提出的顺序机械传输耦合模型适用于一大类的复合材料的同相和它们的特性的适当的选择。对介观结构特征和宏观特性之间关系的定性认识将有助于实验程序的建模和制定方面的未来发展，以改善介观模型的校准和验证。所提出的顺序机械传输耦合模型适用于一大类的复合材料的同相和它们的特性的适当的选择。