中文摘要：

将混凝土视为由骨料、砂浆以及它们之间的界面过渡区（ITZ）组成的细观复合材料,建立了一种包含零厚度粘结单元在内的有限元模型,将粘结单元嵌入到ITZ中以及砂浆单元的边界上,以形成潜在的裂缝发展路径。利用该模型对已生成的二维混凝土试件进行了单轴压缩的数值试验,获得了试件的应力-应变关系曲线以及试件从微裂纹萌发、裂缝开展到最后压溃破坏过程的裂缝演变状态,得到的宏观裂缝及溃裂形态与轴压物理试验十分相近,得到的力学响应曲线与物理试验也呈现良好的一致性。

英文摘要：

Concrete is here regarded as a kind of mesoscopic composite material composed by aggregates, cement mortar and interfacial transition zones （ITZ）. A finite-element model involving zero-thickness cohesive elements is then established. The cohesive elements are embedded in the ITZ and the boundaries of cement mortar elements, along which the potential path of cracking evolution is formed. Using the proposed model, a uniaxial compressive numerical test is carried out to the generated two-dimensional numerical specimen. The stress-strain curve and the cracking patterns of the specimen at different stages from cracking generation and evolution to the final crushing are all presented. The obtained mechanical responses and cracking patterns are much realistic and match the corresponding physical test closely.