RESEARCH ON CARBONATION AND CHLORIDE PROFILES OF CONCRETE AFTER 21 YEARS OF EXPOSURE
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摘要: 对暴露21年的挡浪坝和预制混凝土扭工字块钻取了一批直径100mm的混凝土芯样。在实验室测定了芯样中的碳酸钙含量和氯离子分布;通过压汞试验测定了混凝土表层和内部的孔结构;分析材料因素和环境因素对碳化及氯离子分布的影响。结果表明,在相对湿度较高时,混凝土碳化十分有限,且以未完全碳化区为主导;实际暴露混凝土中氯离子侵入深度不大;暴露混凝土表层与内部的微观结构差异明显,混凝土进一步水化和海水中的物质对表层混凝土的填充对氯离子侵入混凝土内部有阻碍作用。Abstract: The specimens of concrete core with diameter of 100 mm were drilled from wave-preventing dam and concrete blocks.The content of calcium carbonate and chloride distribution from the specimens were measured;pore structure in inner part and in the surface of concrete was measured by mercury intrusion test.Influence of materials and environments on carbonation and chloride distribution was analyzed.The test shows that the carbonation rate is slow in extremely humid environment, and the incomplete carbonation zone is dominated in carbonation.The invading depth of chloride ions is low in exposure condition;difference of the pore structure exists between outer zone and inner zone of exposed concrete, the hydration in proceeding of concrete and the substance of sea water filling in the outer zone of concrete block the chloride ion invading of concrete.
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Key words:
- chloride ion /
- carbonation /
- diffusion coefficient /
- cores /
- pore structure
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? [1] ivica V. Corrosion of Reinforced Induced by Environment?Containing Chloride and Carbon Dioxide [J]. Bulletin of Materials?Science,2003,26(6):605-608. [2] 耿欧,袁迎曙.钢筋混凝土耐久性人工气候加速退化试验的相关性研究[J].混凝土,2004(1):29-31. [3] 张誉,蒋利学.混凝土结构耐久性概论[M].上海:上海科学技术出版社,2003,42-49. [4] 方惠群,虞振新.电化学分析[M].北京:原子能出版社,1984:85-101. [5] Mohammed T U, Hamada H, Yamaji T. Concrete After 30 Years?Exposure-Part II: Chloride Ingress and Corrosion of Steel Bars[J]. ACI Material Journal,2004,101(1):13-18. [6] Taywood Engineering Ltd. Condition Audit of Reinforced Concrete?Piers and Review of Concrete Design for the Marine Environment?Executive Summary[R].1996. [7] Fang Hong, Cao Weiqun, Zhao Tiejun. The Carbonation and?Calcium Leaching in Concrete Under Marine Environment[C]∥ Health Monitoring of Structure, Material and Environment. Nanjing:?Southeast University,2007:1228-1233. [8] 范宏,赵铁军,徐红波.码头混凝土中的氯离子侵入研究[J].水运工程,2006(4):49-54. [9] 吕清芳.混凝土结构耐久性环境区划标准研究[D].杭州:浙江大学,2007. [10] Bamforth P. Definition of Exposure Classes for Chloride?Contaminated Environments.[C]∥ Fourth SCI Conference on?Corrosion of Reinforcement in Concrete Construction.1996:176-190. [11] Arya C , Buenfeld N R, Newman J B. Assessment of Simple?Methods of Determining the Free Chloride Ion Content of Concrete?[J]. Materials and Structures,1990,23:319-330. [12] Maage M, Helland S, Poulson E, et al. Service Life Prediction of?Existing Concrete Structures Exposed to Marine Environment[J]. American Concrete Institute Materials Journal,1996,93(6):602-608.
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