预测混凝土中氯离子扩散的概率密度演化方法

The probability density evaluation method for the prediction of chloride diffusion in concrete

在氯盐环境下,为更加精确地预测混凝土桥梁中的氯离子浓度分布的随机性,将氯离子扩散系数看作服从正态分布的随机变量,通过理论推导建立氯离子浓度分布的概率密度演化方法,并进行变参数分析。结果表明:氯离子浓度概率密度分布的均值随着深度的增加而降低,但其均方差随着深度的增加而增加;氯离子浓度概率密度分布的均值随着扩散时间的增加而增加,但其均方差随着扩散时间的增加而减小;氯离子浓度概率密度分布的均值和均方差均随着扩散系数的均值和均方差而发生一致的变化。

In chloride environment, in order to predicate the randomness of chloride distribution in concrete, supposing diffusion coefficients follow normal distribution, the probability density evolution method was constructed by theoretical derivation, then parameter analysis was carried out. The re-sult shows that： the mean value of probability distribution of chloride concentration decreases with the increase of diffusion depth, but the mean square error of which increases with the increase of dif-fusion depth;the mean value of probability distribution of chloride concentration increases with the increase of diffusion time, but the mean square error of which decreases with the increase of diffu-sion time;the variation of mean value and mean square error of probability density distribution of chloride concentration is similar to that of diffusion coefficient.