This paper presents a numerical study of high strength concrete microstructure effects on its uniaxial and biaxial compressive strengths. Concrete is first represented as a set of angular aggregates interacting within a cement paste matrix. Then, a yield design kinematic approach is conducted at the mesoscopic scale in order to determine the concrete compressive strength for a given loading path. The proposed model, having a low computational cost, is able to capture the main microstructure effects already observed in literature on concrete uniaxial compressive strength, in particular, the aggregates volume fraction and maximal size effects. Finally, the proposed model also predicts the biaxial failure envelope of high strength concrete and confirms some experimental trends observed in literature.

中文翻译：

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基于屈服设计微力学方法的高强混凝土双轴抗压强度数值研究

本文提供了高强度混凝土微观结构对其单轴和双轴抗压强度影响的数值研究。首先将混凝土表示为一组在水泥浆基质中相互作用的角向骨料。然后，在介观尺度上进行屈服设计运动学方法，以确定给定加载路径下的混凝土抗压强度。所提出的模型具有较低的计算成本，能够捕获已经在文献中观察到的关于混凝土单轴抗压强度的主要微观结构效应，特别是骨料的体积分数和最大尺寸效应。最后，提出的模型还预测了高强度混凝土的双轴破坏包络，并证实了文献中观察到的一些实验趋势。