基于贝叶斯机械算法探究氯离子在钢筋混凝土结构中的扩散规律

Chloride Ion Diffusion in Reinforced Concrete Structure Based on Bayesian Mechanical Algorithm

为分析氯盐在钢筋混凝土结构中的传递规律,揭示其扩散机理,采用钢筋混凝土氯盐侵蚀试验来模拟氯盐对钢筋混凝土结构的侵蚀过程.以Fick第二扩散定律误差函数解析解为基础,考虑到测试数据的质量和数量以及回归计算过程中所产生的系统误差对预测模型精度的影响,通过贝叶斯理论对该预测模型进行修正,分别得到钢筋非前沿区域及前沿区域的氯离子扩散预测模型.结果表明:氯盐侵蚀钢筋混凝土基体主要以扩散为主,钢筋的阻滞效应使得钢筋前沿区域5 mm范围内的氯离子浓度提高.

Physical experiment was carried out to investigate the chloride diffusion in reinforced concrete structures. Two prediction models were established to predict the chloride concentration in the non-frontier area and the front area of the steel bar respectively,based on the analytical solution of error function of Fick’s second diffusion law. Considering the effect of quality and quantity of test data and the systematic error produced in the regression calculation process on the accuracy of the prediction model,Bayesian theory was used to modify these prediction models. The results indicate that chloride transport in reinforcement structures mainly depends on diffusion. The chloride concentration within 5 mm of the apex of steel bar will be increased due to the blocking effect of steel bars.