钢筋混凝土氯离子扩散与寿命预测CA模型研究

Research on CA Model of Chloride Ion Diffusion and Service Life Prediction of Reinforced Concrete

氯盐侵蚀会引起钢筋锈蚀,造成其保护层开裂,进而导致结构性能退化。研究氯离子在混凝土内扩散原理以及钢筋初始锈蚀时间,对钢筋混凝土结构耐久性及寿命预测有重要意义。本文利用元胞自动机(CA)原理,建立模拟钢筋混凝土内氯离子扩散过程的CA模型,该模型考虑了时间效应、水灰比和温度的影响。基于建立的CA模型,通过编写Matlab程序,分析钢筋混凝土板、钢筋混凝土方形和圆形柱中一维和二维氯离子扩散行为,并预测钢筋初始锈蚀时间。研究结果及与现有解析解和数值解比较表明,本文建立的模型是正确、有效的,与其他数值方法相比精度更高。

Chloride attack will cause corrosion of steel bar, and thus leads to the cracking of concrete cover and the deterioration of structural performance. To study the mechanism of chloride ion diffusion in concrete and the initial corrosion time of steel bar has a profound practical significance in predicting the durable service life of reinforced concrete. In this paper, a cellular automata （CA） model was established to simulate the diffusion process of chloride ion in reinforced concrete based on the CA principle. This model considers the effects of time variation, water cement ratio and temperature. Based on the CA model, by using the MATLAB pro-grams ,one and two dimensional chloride diffusion processes in reinforced concrete slabs, square and circular reinforced concrete columns were analyzed to predict the initial corrosion time of steel bars. The present re-sults ,compared with the existing analytical solutions and numerical solutions, show that the proposed model is correct and effective, and generates more accurate results than the other numerical methods do.