氯离子在非饱和混凝土中传输过程的数值模拟

Numerical Simulation of Chloride Transportation Process in Unsaturated Concrete

摘要:

为确定氯离子在非饱和混凝土构件中的传输过程,推导了基于物质守恒定律的氯离子对流扩散方程;并对控制方程中的计算参数以及有限元计算过程的稳定性进行了初步讨论.在此基础上,定量分析了对流效应对氯离子传输过程的影响.分析结果表明,对流和扩散效应的耦合作用主要出现于构件表层;对流效应在传输过程初期较为显著.最后,对计算模型的参数敏感性分析结果表明,水分和氯离子的扩散系数比对氯离子传输过程影响较大.

Abstract:

In order to describe the chloride transportation process in unsaturated concrete components,the convection-diffusion equation of chloride was developed based on the mass conservation law.The parameters in the governing equation and the stabilization of FEM solution process were preliminary discussed.Based on the discussion,the influence of convection effect on chloride transportation process was analyzed quantitatively.The results show that the coupled effect of convection and diffusion will mainly occur in the surface layer of components,and the convection effect will be more obvious in the initial stage of transportation process.Finally,the results of the parameter sensitivity analysis of the numerical model show that the diffusion coefficient ratio between moisture and chloride will greatly affect the chloride transportation process.