混凝土氯离子侵蚀的概率分析

Probabilistic Analysis for Chloride Penetration Inside Concrete

目前的混凝土结构在氯离子环境下的寿命预测多以确定性方法进行,而基于概率的氯离子侵蚀寿命预测方法能够更加科学合理地反映工程实际。为了表明该寿命预测方法的这一优点,通过Monte Carlo方法对4组数据分别进行概率法寿命和确定法寿命的计算,并将其结果进行了分析比较,得出概率法的寿命预测具有更高的保证率,从而说明了概率法寿命预测方法更具科学性。同时进行了概率法模型的参数分析,可知增加混凝土保护层厚度和提高材料的抗渗性能是提高混凝土耐久性的重要方法,为实际工程提供一定的参考依据。

Nowadays the decisive method of life period prediction for concrete structures under chloride penetration is always used, but probability-based life period prediction method can accord with engineering practices more scientifically and reasonably. In this paper, two kinds of calculation based on 4 groups of data, including decisive and probabilistic life period prediction, were respectively given by Monte Carlo method. After analysis and comparison, a conclusion was drawn that probability-based life period prediction has higher guarantee rate, which demonstrates it more scientific. Also a sensitivity analysis of parameters for probabilitybased life period prediction model was given. It shows that increasing the thickness of concrete cover and improving concrete impermeability were two important approach to durability improvement.