| 摘要: |
| 为探究滨海环境中干湿循环的不规律性对混凝土表层氯离子传输的影响，设计了连续、非连续干湿循环对比试验，研究了不同干湿循环下水灰比和干湿循环制度对混凝土表层氯离子含量分布规律及对流区氯离子含量变化规律的影响.结果表明：当自然风干时间/湿润时间（td/tw）较大时，由于双向对流与扩散的传输现象，使得氯离子含量在对流区存在1个拐点；对流区深度基本随水灰比减小而减小；连续干湿循环下氯离子峰值含量随着td/tw的减小而增大；相较于连续干湿循环而言，非连续干湿循环对表层氯离子含量随深度的变化规律和氯离子峰值含量的影响较大. |
| 关键词: 混凝土结构 非连续干湿循环 混凝土表层氯离子含量 对流区 |
| DOI：10.3969/j.issn.1007-9629.2023.02.004 |
| 分类号:TU528.01 |
| 基金项目:滨海城市韧性基础设施教育部重点实验室项目（ZDSYS20201020162400001）； 国家自然科学基金资助项目（52178233）；广东省住房城乡建设科技协同创新中心专项课题二（2018B020207015）； 广东省科技厅重点研发项目子课题（2019B111106002）；深圳市科技创新委员会孔雀团队项目（KQTD20180412181337494）；广东省珠江学者岗位资助计划项目（GDHVPS2021）；深圳市科技支撑计划项目（GJHZ20210705141802009，JCYJ20220531101605012） |
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| Effects of Discontinuous Dry-Wet Cycles on Migration of Chloride in Concrete Cover |
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ZHOU Zonglong1,2, ZHONG Zhiheng1, MA Cong1, LIU Jian3, ZHOU Haijun1,4
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1.College of Civil and Transportation Engineering， Shenzhen University， Shenzhen 518060， China;2.Shenzhen Metro Construction Group Co.，Ltd.， Shenzhen 518060， China;3.Shenzhen-Zhongshan Bridge Management Center， Zhongshan 528400， China;4.Key Laboratory for Resilient Infrastructures of Coastal Cities， Ministry of Education， Shenzhen University， Shenzhen 518060， China
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| Abstract: |
| In order to study the effect of the irregularity of dry-wet cycles on chloride transmission in concrete cover under marine environment， comparative tests under continuous and discontinuous dry-wet cycles were carried out. The effect of water-cement ratio and dry-wet cycles regime under different dry-wet cycles on the distribution of chloride content in concrete cover and the change of choloride content in convection zone was studied. The results show that the chloride content has an inflection point in the convection zone due to the transmission phenomenon of bidirectional convection and diffusion when the time of dry-wet ratio（td/tw） is relatively high. The depth of convection zone decreases as the mass of water-cement ratio decreases， while the peak chloride content increases with the reduction of td/tw. Compared with continuous dry-wet cycles， the discontinuous dry-wet cycles have a significant effect on the variation of chloride content with the depth and the peak chloride content in the concrete cover. |
| Key words: concrete structure discontinuous dry-wet cycle chloride content in concrete cover convection zone |
