Yang Anyu, Shang Qizhi, Zhang Yanan, Zhu Junlong
Nanjing Hydraulic Research Institute, Nanjing 210024, China.
National Research Institute for Rural Electrification of MWR, Hangzhou 310000, China.
Materials (Basel). 2024 May 24;17(11):2532. doi: 10.3390/ma17112532.
Recycled concrete is a heterogeneous composite material, and the composition and volume fraction of each phase affect its macroscopic properties. In this paper, ANSYS APDL was used to construct a two-dimensional numerical model of recycled aggregate concrete with different replacement rates of recycled aggregate (0%, 25%, 50%, 75% and 100%), and a uniaxial compression test was carried out to explore the relationship between recycled aggregate content and its macroscopic mechanical behavior. On this basis, the numerical simulation of different strain rates (0.1 s, 0.05 s, 0.01 s, 0.005 s and 0.001 s) was carried out. It was found that with the increase in the recycled aggregate replacement rate, the peak stress decreases first and then increases, and the peak strain increases continuously. When the replacement rate of recycled aggregate exceeds 50%, the overall damage area of the material increases rapidly. The strain rate will change the path of the micro-crack initiation and expansion of recycled concrete, as well as the process of damage accumulation and evolution. As a result, the unit area and shape of recycled concrete are different at different strain rates, and the damage degree of each phase material is also different.
再生混凝土是一种多相复合材料，各相的组成和体积分数会影响其宏观性能。本文利用ANSYS APDL建立了再生骨料取代率不同（0%、25%、50%、75%和100%）的再生骨料混凝土二维数值模型，并进行了单轴压缩试验，以探究再生骨料含量与其宏观力学行为之间的关系。在此基础上，对不同应变率（0.1s、0.05s、0.01s、0.005s和0.001s）进行了数值模拟。结果表明，随着再生骨料取代率的增加，峰值应力先减小后增大，峰值应变不断增大。当再生骨料取代率超过50%时，材料的整体损伤面积迅速增大。应变率会改变再生混凝土微裂纹起裂和扩展的路径，以及损伤累积和演化的过程。因此，再生混凝土在不同应变率下的单元面积和形状不同，各相材料的损伤程度也不同。
