考虑荷载作用效应的混凝土中氯离子扩散细观数值模拟

Micro-scale numerical simulation of chloride diffusion in concrete under load effect

混凝土结构在海洋环境中不只遭受氯离子的侵蚀,并且还承受荷载作用。文章将混凝土看作由固化水泥砂浆、界面过渡区与碎石粗骨料构成的三相复合材料,认为氯离子传输扩散行为只发生在固化水泥砂浆和界面过渡区中;基于荷载作用使混凝土孔隙率发生变化、孔隙率变化导致氯离子扩散系数变化的假设,提出了考虑荷载作用效应的混凝土中氯离子扩散系数模型,并用物理试验实测值对细观数值模型进行了验证。通过对受荷简支梁氯离子扩散细观数值模拟,分析了荷载水平对氯离子扩散规律的影响,为研究荷载作用下混凝土内氯离子扩散特性提供了一种有效手段。

Under the condition of marine,the concrete structure is not affected only by chloride erosion,but load.At the meso-scale,concrete is modeled as a 3-phase composite material composed of mortar,coarse aggregate and interfacial transition zone(ITZ),chloride diffusion could only occurs in mortar and ITZ.Based on the assumption that the load transformed the porosity of concrete and this change leads to the transformation of chloride ion diffusivity,this paper proposed a kind of chloride ion diffusivity model in concrete which is under load and this mesoscale model was verified through physical experiment measured values.It analysed the effect of stress level on the regulation of chloride diffusion through simulated the data of free beam under load chloride diffusion in mesoscale model,which provided an effective method for studying the chloride diffusion of concrete under load.