基于元胞自动机的混凝土氯离子扩散与渗透模拟与分析

Simulation and analysis of the chloride ions diffusion and penetration effect in concrete based on cellular automata

为从结构层面上模拟氯离子对混凝土的侵蚀效应、有针对性地进行老化结构的维护和修复,提出一种新的模拟氯离子在混凝土内扩散的算法模型-空间非规则单元元胞自动机模型。该模型可以同时考虑浓度梯度引起的扩散作用和压力梯度引起的渗透作用。在此研究基础上,以某沿海典型钢筋混凝土桥梁为背景,建立空间三维有限元模型,用所提出的理论模型编写了MATLAB程序,对该桥梁的氯离子扩散和渗透过程进行模拟。理论计算值与桥梁各构件现场氯离子检测值的对比结果表明,所提出的模型能有效地预测氯离子在混凝土中的扩散和渗透,具有工程实际意义。

In order to simulate the chloride ion erosion effect on the concrete at structural level and conduct the maintenance and repair of aging concrete structures effectively,a new algorithm model for simulating chloride ion diffusion and penetration in concrete,which is called spatial irregular element cellular automata model,is proposed. The proposed model can take the diffusion effect caused by concentration gradient and the penetration effect by pressure gradient into consideration. Taking a typical reinforced concrete bridge located in coastal area as an engineering background,the spatial 3D FE model is established. The program is written by MATLAB according to the proposed cellular automata model theory. By simulating and analyzing chloride ion diffusion and penetration process of the concrete bridge,the results predicted by the proposed cellular automata model of chloride concentration are compared with the field tested results. The results show that the proposed model can effectively predict the diffusion and penetration of chloride ion in concrete structures and has practical significance.