Influence of Spatial Distribution of Chloride Ion Concentration on Non-Uniform Corrosion of Reinforcement in Concrete
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摘要: 为探究混凝土表面氯离子浓度空间分布下的钢筋非均匀腐蚀规律,构建了物质传输-钢筋电化学腐蚀耦合模型。基于真实海洋环境下混凝土表面氯离子浓度分布数据,分析了内部钢筋的表面自由氯离子浓度分布、电流密度分布以及非均匀腐蚀形态。结果表明:纵向上的钢筋表面自由氯离子浓度与混凝土表面氯离子浓度分布特征基本一致,但环向上氯离子发生的迁移使钢筋与混凝土的表面氯离子浓度发展规律有差异,混凝土表面氯离子空间分布使钢筋在纵向和环向上均呈现非均匀腐蚀形态,但非均匀腐蚀程度会随时间推移呈现先增大后减小趋势。Abstract: In order to explore the reinforcement non-uniform corrosion under the influence of the spatial distribution characteristics of surface chloride ion concentration, a coupling model of mass transport and reinforcement electrochemical corrosion was constructed in this paper. Based on the surface chloride concentration data of concrete in real marine environment, the free chloride concentration distribution, current density distribution and corrosion form of internal reinforcement were analyzed. The results show that the distribution characteristics of surface chloride ion concentration of reinforcement and concrete are basically the same in the longitudinal direction, but the migration of chloride ion in the circumferential direction makes the development law of surface chloride ion concentration of reinforcement and concrete different. In circumferential direction, micro cell corrosion of reinforcement starts from the side with high surface chloride ion concentration of the concrete and develops into uniform corrosion on the whole section.
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