基于三维非凸骨料的混凝土模型在氯离子侵蚀下的模拟研究

Simulation of concrete model based on three-dimensional non convex aggregates under chloride ion erosion

氯离子在混凝土中的扩散会受到其细观结构的影响,而骨料的影响是极其重要的一方面,研究更符合真实形状骨料对氯离子扩散的影响是有意义的。利用单位球收缩法并通过水平集函数构建了三维非凸骨料随机堆积结构。利用Abaqus二次开发读取数据,从而构建含有骨料、ITZ、基体的三相混凝土细观模型,再通过有限元数值模拟得到的计算结果与解析解和试验结果进行对比,验证了有限元模型的可行性和有效性。最后探究了混凝土细观结构对氯离子扩散的影响,得出混凝土界面过渡区和粗骨料对混凝土中氯离子扩散的影响规律。

The diffusion of chloride ions in concrete is influenced by its microstructure,and the influence of aggregates is an extremely important aspect.Therefore,it is meaningful to study the effect of aggregates with more realistic shapes on chloride ion diffusion.Therefore,we utilized the unit ball shrinkage method and constructed a 3D non convex aggregate random stacking structure through a level set function.Using Abaqus secondary development to read data,a three-phase concrete microstructure model containing aggregates,ITZ,and matrix was constructed.The feasibility and effectiveness of the finite element model were verified by comparing the calculated results obtained from finite element numerical simulation with analytical and experimental results.Finally,the influence of concrete microstructure on chloride ion diffusion was explored,and the influence of concrete interface transition zone and coarse aggregate on chloride ion diffusion in concrete was obtained.