Abstract The chloride-induced steel corrosion is one of the main causes of deterioration for reinforced concrete structures exposed to marine environments. The chloride ingress into reinforced concrete structures is even more complex since it depends on random parameters linked to transport and chemical properties of materials, which results in variability of corrosion initiation. This variation raises the need of statistical approaches to evaluate the risk of corrosion initiation due to chloride ingress. To address this issue, we use sensitivity analysis to identify the influence of input parameters on critical length of time before corrosion initiation predicted by our chloride diffusion model. Exceedance probabilities of corrosion initiation time given that input parameters exceed certain thresholds were also calculated. Results showed that the corrosion initiation time was most sensitive to: chloride effective diffusion coefficient De in concrete, that is a parameter controllable by relevant stakeholders; surface chloride concentration Cs, a non-controllable parameter depending on surrounding conditions. Reducing the chloride diffusion coefficient enables us to postpone the maintenance of structures. However, the interaction between controllable parameters and non-controllable surrounding conditions was revealed influential on the reliability of results. For instance, the probability that corrosion initiation time exceeds 15 years given an effective diffusion coefficient (De) equal to 0.1 × 10−12 m2⋅s-1 can vary from 19 to 41% according to stochastic variations of chloride concentrations (Cs) values. Postponing the corrosion initiation time was combined with a decreasing probability of its occurrence.

中文翻译：

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海洋环境中混凝土结构氯离子扩散腐蚀风险分析

摘要 氯化物引起的钢筋腐蚀是暴露于海洋环境的钢筋混凝土结构劣化的主要原因之一。氯化物进入钢筋混凝土结构甚至更加复杂，因为它取决于与材料的运输和化学性质相关的随机参数，这会导致腐蚀开始的可变性。这种变化需要采用统计方法来评估由于氯化物进入而引发腐蚀的风险。为了解决这个问题，我们使用敏感性分析来确定输入参数对我们的氯化物扩散模型预测的腐蚀开始前临界时间长度的影响。还计算了输入参数超过特定阈值时腐蚀开始时间的超过概率。结果表明，腐蚀开始时间对混凝土中氯化物有效扩散系数De最敏感，该参数是相关利益相关者可控的参数；表面氯化物浓度 Cs，一个取决于周围条件的不可控参数。降低氯化物扩散系数使我们能够推迟结构的维护。然而，可控参数和不可控周围条件之间的相互作用对结果的可靠性有影响。例如，在有效扩散系数 (De) 等于 0.1 × 10−12 m2⋅s-1 的情况下，腐蚀开始时间超过 15 年的概率可以根据氯化物浓度 (Cs) 值的随机变化在 19% 到 41% 之间变化.