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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[1] 金伟良,赵羽习. 混凝土结构耐久性[M]. 北京:科学出版社, 2014. [2] XIA J, SHEN J, LI T, et al. Corrosion prediction models for steel bars in chloride-contaminated concrete: a review[J]. Magazine of Concrete Research, 2022, 74(3): 123-142. [3] YANG L, WANG L, YU B. Time-varying behavior and its coupling effects with environmental conditions and cementitious material types on surface chloride concentration of marine concrete[J/OL]. Construction & Building Materials, 2021, 303[2022-05-03].https://doi.org/10.1016/j.conbuildmat.2021.124578. [4] 杨绿峰,蔡荣,余波. 海洋大气区混凝土表面氯离子浓度的形成机理和多因素模型[J]. 土木工程学报, 2017, 50(12): 46-55. [5] YANG L F, CAI R, YU B. Investigation of computational model for surface chloride concentration of concrete in marine atmosphere zone[J]. Ocean Engineering, 2017, 138: 105-111. [6] 胡劲哲,牛建刚,孙丛涛,等. 海洋大气区氯离子在混凝土中的沉积与传输行为研究综述[J]. 土木与环境工程学报(中英文), 2020, 42(2): 165-178. [7] CAO J, JIN Z, DING Q, et al. Influence of the dry/wet ratio on the chloride convection zone of concrete in a marine environment[J/OL]. Construction & Building Materials, 2022, 316[2022-05-03].https://doi.org/10.1016/j.conbuildmat.2021.125794. [8] LIU Q, SUN L, ZHU X, et al. Chloride transport in the reinforced concrete column under the marine environment: Distinguish the atmospheric, tidal-splash and submerged zones[J]. Structures (Oxford), 2022, 39: 365-377. [9] LIAM K C, ROY S K, NORTHWOOD D O. Chloride ingress measurements and corrosion potential mapping study of a 24-year-old reinforced-concrete jetty structure in a tropical marine-environment[J]. Magazine of Concrete Research, 1992, 44(160): 205-215. [10] 姚昌建. 沿海码头混凝土设施受氯离子侵蚀的规律研究[D]. 杭州:浙江大学, 2007. [11] 张奕,姚昌建,金伟良. 干湿交替区域混凝土中氯离子分布随高程的变化规律[J]. 浙江大学学报(工学版), 2009, 43(2): 360-365. [12] ZHAO Y, HU B, YU J, et al. Non-uniform distribution of rust layer around steel bar in concrete[J]. Corrosion Science, 2011, 53(12): 4300-4308. [13] JANG B S, OH B H. Effects of non-uniform corrosion on the cracking and service life of reinforced concrete structures[J]. Cement and Concrete Research, 2010, 40(9): 1441-1450. [14] YUAN Y, JI Y. Modeling corroded section configuration of steel bar in concrete structure[J]. Construction and Building Materials, 2009, 23(6): 2461-2466. [15] 李天. 氯盐环境混凝土内部钢筋非均匀腐蚀机理与数值模拟研究[D]. 杭州:浙江大学, 2020. [16] HU J, DENG P, LI X, et al. The vertical non-uniform corrosion of reinforced concrete exposed to the marine environments[J]. Construction & Building Materials, 2018, 183: 180-188. [17] LIU Q, EASTERBROOK D, YANG J, et al. A three-phase, multi-component ionic transport model for simulation of chloride penetration in concrete[J]. Engineering Structures, 2015, 86: 122-133. [18] 李仁民,刘松玉,方磊,等. 基于微观PNP多离子运移模型的多孔介质曲率系数分析[J]. 东南大学学报(自然科学版), 2011, 41(3): 647-651. [19] ANDRADE C, ALONSO C. Corrosion rate monitoring in the laboratory and on-site[J]. Construction & Building Materials, 1996, 10(5): 315-328. [20] KIM C, KIM J. Numerical analysis of localized steel corrosion in concrete[J]. Construction and Building Materials, 2008, 22(6): 1129-1136.
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