基于离散元的水泥混凝土细观模拟试验

Simulation Test of Cement Concrete in Meso-scale Based on Discrete Element Method

为研究水泥混凝土力学特性及破坏机理,考虑水泥混凝土的非均匀特性及细观结构组成,首先利用离散元软件PFC2D进行水泥混凝土抗压强度细观数值模拟试验,对混凝土的破坏过程及强度形成机理进行分析,得到其弹性模量和抗压强度。并分析细观组成参数对其弹性模量和抗压强度的影响,通过不断调试和校核给出混凝土不同强度等级下的细观参数推荐值。然后,以推荐的混凝土细观参数为基础,依次进行水泥混凝土弯拉强度和抗剪强度模拟试验,分别得出不同强度等级下的混凝土弯拉强度和抗剪强度。最后,将所得数值模拟试验结果与室内试验结果进行对比。研究结果表明:利用离散元软件对水泥混凝土抗压强度、弯拉强度及抗剪强度进行数值模拟,进而对混凝土强度形成机理及破坏过程进行研究是可行的。

In order to research the mechanical characteristics and failure mechanism of cement concrete,the non-uniform characteristics and meso-structure of cement concrete are considered. First,the compressive strength simulation test of cement concrete in meso-scale is conducted by using discrete element software PFC2 D,the destruction process and the strength formation mechanism of cement concrete are analyzed,and its elastic modulus and compressive strength are obtained. Then,the effects of meso-structure parameters on the elastic modulus and compressive strength are analyzed,and the meso-structure parameters for different strength grades of cement concrete are recommended. After that,based on the recommended meso-structure parameters of cement concrete,the flexural-tensile strength and shear strength tests on the cement concrete are carried out,and the flexural-tensile strength and shear strength of for different strength grades of cement concrete are obtained. At last,the result of numerical simulation test is compared with the result of laboratory test. The result indicates that using the discrete element software to simulate the tests of compressive strength,flexural-tensile strength and shear strength and study the strength formation mechanism and destruction process of cement concrete are feasible.