Chloride-induced corrosion is a primary cause of performance degradation and lifespan attenuation in reinforced concrete (RC) structures in marine and de-icing salt environments. This paper focuses on identifying and modeling the uncertainty of chloride transport induced by the mesoscopic structure of concrete. Utilizing mesoscopic statistics conducted on random concrete specimens with different volume fractions, this investigation elucidates the probabilistic characteristics and the spatial and temporal variation of chloride concentration and diffusion coefficients. Building on the quantitative relationships and Spearman correlations between aggregate characteristic parameters and chloride diffusion coefficients derived from mesoscopic statistics, a prediction model for chloride diffusion coefficients incorporating aggregate volume fractions and particle sizes was developed and validated. On this basis, a mesoscopic probabilistic framework for chloride diffusion coefficients was proposed. The findings reveal the spatial and temporal variability in chloride concentration and diffusion coefficient. The chloride concentration approximates a normal or log-normal distribution, whereas the diffusion coefficient approximates a log-normal distribution. The chloride diffusion coefficient generally shows a noticeable positive Spearman correlation with the maximum and average aggregate sizes and a negative correlation with the aggregate particle number. The research is beneficial for probabilistic chloride transport and lifespan estimation in RC structures.

中文翻译：

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介孔结构引起的混凝土中氯化物传输的不确定性


氯化物引起的腐蚀是海洋和除冰盐环境中钢筋混凝土 （RC） 结构性能下降和寿命衰减的主要原因。本文的重点是识别和模拟混凝土介观结构引起的氯化物传输的不确定性。利用对具有不同体积分数的随机混凝土样品进行的细观统计，本研究阐明了氯化物浓度和扩散系数的概率特征以及空间和时间变化。基于从细观统计得出的聚集体特征参数和氯化物扩散系数之间的定量关系和 Spearman 相关性，开发并验证了包含聚集体体积分数和粒径的氯化物扩散系数预测模型。在此基础上，提出了氯化物扩散系数的细观概率框架。研究结果揭示了氯化物浓度和扩散系数的空间和时间变化。氯化物浓度近似于正态分布或对数正态分布，而扩散系数近似于对数正态分布。氯化物扩散系数通常与最大和平均聚集体粒径呈明显的正 Spearman 相关，与聚集体颗粒数呈负相关。该研究有利于 RC 结构中的概率氯离子传输和寿命估计。