受力状态下混凝土试件氯离子侵蚀试验.pdf

中国科技论文在线 受力状态下混凝土试件氯离子侵蚀试验# 李国平，胡方健，吴用贤* （同济大学桥梁工程系，上海 200092 ） 5 摘要：氯离子侵入而导致的钢筋锈蚀现象是混凝土桥梁的常见病害之一，因此混凝土抵抗氯 离子侵入的能力对其耐久性有重要影响。进行氯离子侵蚀试验是研究氯离子侵入规律的有效 手段，但目前的研究成果大部分是针对无应力状态下的普通混凝土，对处于受力状态下的混 凝土研究很少。为了研究受力状态下混凝土的抗氯离子侵入性能，对混凝土进行了盐溶液浸 泡和盐雾试验，得出未开裂的试件在不同水灰比、受力状态、应力水平和作用环境下的试验 10 结果，并对其进行对比分析。试验结果表明：减小水灰比能提高混凝土的抗氯离子侵蚀能力； 在拉应力状态下的氯离子含量比无应力状态下的要多；在压应力状态下的氯离子含量取决于 压应力水平；盐溶液浸泡环境对混凝土结构的作用比盐雾严重得多。 关键词：桥梁工程；混凝土；氯离子侵蚀；应力状态；浸泡；盐雾 中图分类号：U444 15 Chloride Ion Penetration in Stressed Concrete LI Guoping, HU Fangjian, Wu Yongxian (Department of Bridge Engineering, Tongji University, shanghai 200092, China) Abstract: Steel corrosion due to chloride ion penetration is one of the most common problems 20 related to the durability of concrete bridges. Although previous studies of this phenomenon have produced useful results, they focused mainly on unstressed concrete. To study the effect of stress on the resistance of concrete to chloride ion penetration, tests of stressed specimens exposed to salt solution immersion and salt spray were performed. The chloride content in uncracked concrete specimens with different water-cement ratios, states and levels of stress, and environmental 25 conditions are given and analyzed in this article. The results show that the resistance of concrete to chloride ion penetration can be improved by reducing the water/cement ratio. For concrete stressed in tension, the content of chloride ions is higher than for unstressed concrete. For concrete stressed in compression, chloride content depends on stress level. Salt solution immersion is more severe than salt spray. 30 Key words: Bridge engineering; Concre