2304不锈钢钢筋在港珠澳大桥的应用——钢筋耐蚀性能研究  

Use of 2304 Stainless Steel Reinforcement in Hong Kong-Zhuhai-Macao Bridge——Corrosion Behaviors of 2304 Stainless Steel Reinforcement

作　　者：景强 方翔[2,3] 倪静姁 汤雁冰[2,3] JING Qiang FANG Xiang NI Jing-xu TANG Yan-bing(Hong Kong- Zhuhai- Macao Bridge Authority, Zhuhai Guangdong 519015, China CCCC Fourth Harbor Engineering Institute Co. , Ltd. , Guangzhou Guangdong 510230, China Key Laboratory of Durability Technology for Harbor and Marine Structure Ministry of Communication, Guangzhou GuangdongS10230, China)

机构地区：[1]港珠澳大桥管理局,广东珠海519015 [2]中交四航工程研究院有限公司,广东广州510230 [3]交通运输部水工构造物耐久性技术交通行业重点实验室,广东广州510230

出　　处：《公路交通科技》2017年第10期51-56,共6页Journal of Highway and Transportation Research and Development

基　　金：国家科技支撑计划项目(2011BAG07B04)

摘　　要：港珠澳大桥是我国内地第一个采用不锈钢钢筋的工程。为消除工程中使用国产不锈钢钢筋的疑虑,对不锈钢钢筋的耐蚀性能以及不锈钢钢筋与碳钢钢筋搭接可能产生的电偶腐蚀问题进行了研究。通过M-S曲线研究比较了碳钢钢筋(Q235)、304L、316L和2304不锈钢钢筋钝化膜特性。通过测量2304不锈钢钢筋在含氯盐的模拟混凝土孔隙溶液中的极化曲线确定其临界氯离子浓度。结果显示2304不锈钢钢筋在此环境中的临界氯离子浓度与316L相近,几十倍于碳钢钢筋。通过零电阻法获取不锈钢钢筋与碳钢钢筋在混凝土中接触所产生的电偶腐蚀电流密度。不锈钢钢筋与碳钢钢筋搭接会产生电偶腐蚀,当两者都处在钝化状态时,电偶腐蚀电流可忽略;当不锈钢处于钝化状态,而碳钢钢筋已经活化时,电偶腐蚀对碳钢钢筋腐蚀的增加只有几个百分点。电偶腐蚀电流随着两者距离及面积比分别呈线性和指数减少的趋势。Hong Kong-Zhuhai-Macao Bridge is the first project in the mainland of China that uses stainless steel reinforcements. In order to eliminate the doubts of using domestically made stainless steel reinforcement in the project,researches on the corrosion resistance of 2304 stainless steel reinforcements as well as on the galvanic corrosion issue resulting from the direct contact of the stainless steel and carbon steel reinforcements in concrete have been carried out. The characteristics of the passivation film form on carbon steel（ Q235）,304 L,316L and 2304 stainless steel reinforcement were compared with Mott-Schottky curves. Polarization curves of 2304 stainless steel obtained in simulated concrete pore solution added with chlorides were used to determine critical chloride concentration of 2304 stainless steel. Results show that critical chloride concentration of 2304 stainless steel is similar to that of 316 L stainless steel,and several ten times to that of carbon steel. Galvanic current density was obtained with zero resistance amperemeter to determine the galvanic corrosion caused by direct contact of stainless steel and carbon steel reinforcements in concrete. The direct contact of stainless steel and carbon steel will lead to galvanic corrosion. Galvanic current density isneglectable when both steel are in passivated state. When carbon steel reinforcements are in active steel and stainless steel reinforcements remain in passivated state,galvanic corrosion will increase the corrosion rate of carbon steel for just several percent. Galvanic current densities between stainless steel and carbon steel reinforcement decrease in linear and exponential manner respectively as the distance and surface area ratio or the two reinforcements increase.

关 键 词：桥梁工程 临界氯离子浓度 电偶腐蚀 不锈钢钢筋 港珠澳大桥 

分 类 号：U444[建筑科学—桥梁与隧道工程]