考虑热湿度及压应力作用的混凝土氯离子扩散数值分析

Numerical Analysis of Chloride Ion Diffusion in Concrete Considering Thermal Humidity and Compressive Stress

如何预测氯离子在热湿度及压应力作用下的侵蚀过程是混凝土结构工程师面临的严峻挑战。利用系数形式偏微分方程建立了考虑环境变量、应力水平耦合的氯离子模型控制方程,控制方程中所涉及的参数均有参考的依据。为能再现混凝土结构在热湿度及压应力条件下的真实情况,通过有限元软件构建了二维混凝土骨料模型,并将模型控制方程与骨料模型结合起来,建立氯离子扩散的数值分析方法,探讨二维混凝土骨料模型中氯离子侵蚀过程随环境湿度、温度及应力水平变化的规律。模型计算结果与试验数据具有良好的吻合度,研究结果可为混凝土结构的减防腐蚀灾害设计提供参考。

How to predict the erosion process of chloride ions under the action of thermal humidity and compressive stress is a severe challenge faced by concrete structure engineers.The control equation of chloride ion model considering the coupling of environmental variables and stress levels is established by using partial differential equation in coefficient form.All the parameters involved in the control equation have reference basis.In order to reproduce the real situation of concrete structure under the conditions of thermal humidity and compressive stress,a two-dimensional concrete aggregate model was built by finite element software.Combining the model control equation with aggregate model,the numerical analysis method of chloride ion diffusion is established.Based on the numerical analysis method,the laws of chloride ion erosion process with environmental humidity,temperature and stress level in two-dimensional concrete aggregate model are discussed.The calculated results of the model are in good agreement with the experimental data.The research results can provide reference for the design of concrete structures to reduce and prevent corrosion disasters.