水工三级配及湿筛混凝土单轴受压力学特性细观数值模拟

Meso-Numerical Simulation for the Mechanical Properties of Three-Grade and Wet-Sieved Concrete under Uniaxial Compression

为了研究水工大骨料混凝土单轴受压的力学特性,运用颗粒流离散元软件PFC 2D建立三级配大骨料混凝土试件模型,通过将单轴压缩数值模拟得到的强度与已有文献中三级配大骨料混凝土试验数据进行对比,标定出水工大骨料混凝土中砂浆颗粒间的接触参数、粗骨料颗粒间的接触参数以及砂浆与粗骨料接触面的细观参数,将标定出的接触参数运用到湿筛混凝土中进行单轴压缩数值模拟。结果表明,在相同细观参数情况下,湿筛混凝土破坏形态与大骨料混凝土相近,裂缝数量较多;二级配湿筛混凝土试件的强度为三级配大骨料混凝土试件强度的1.25倍,两者的应力-应变曲线形状相近,峰值处应变为大骨料试件的1.2倍。研究成果可为水工大骨料混凝土力学性能研究提供借鉴。

In order to study the mechanical properties of three-grade and wet-sieved concrete under uniaxial compression,the particle flow discrete element software PFC 2D is used to establish a three-grade large aggregate concrete specimen model.The strength obtained by numerical simulation of uniaxial compression is comparable to the data in the literature,and the contact parameters between the mortar particles in the hydraulic large aggregate concrete,the contact parameters between the coarse aggregate particles,and the meso parameters of the contact surface between the mortar and the coarse aggregate were calibrated.The calibrated contact parameters are applied to the wet screened concrete for uniaxial compression numerical simulation.The results show that under the same meso-parameters,the failure form of wet-sieved concrete is similar to that of large aggregate concrete,and the number of cracks is larger;the strength of the two-grade wet-sieved concrete specimen is 1.25 times that of the three-grade large aggregate concrete specimen.The stress-strain curves of the two are similar in shape,and the peak strain is 1.2 times that of the large aggregate specimen.The research results can provide reference for the research on the mechanical properties of hydraulic aggregate concrete.