兰州地铁地下水环境中钢筋混凝土通电锈蚀机理研究  

Study on Energized Corrosion Mechanism of Reinforced Concrete in Groundwater Environment of Lanzhou Metro

作　　者：乔国斌 乔宏霞[1,2] 路承功 QIAO Guobin;QIAO Hongxia;LU Chenggong(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Western Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学土木工程学院,兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,兰州730050

出　　处：《材料导报》2022年第19期114-119,共6页Materials Reports

基　　金：国家自然科学基金(51168031,51868044);兰州理工大学红柳一流学科建设计划资助。

摘　　要：针对兰州地铁一号线地下水环境含有大量侵蚀离子导致混凝土中钢筋过早锈蚀的问题,本工作通过模拟地下水环境对三种不同水胶比的钢筋混凝土试件进行通电加速锈蚀试验,利用电学无损检测法表征钢筋腐蚀程度,辅以微观检测手段验证试验结果,综合分析混凝土内钢筋腐蚀规律。最终推导并定义锈蚀系数k作为表征钢筋锈蚀程度的评价参数,并验证其合理性。结果表明:随着通电腐蚀的加剧,钢筋电阻值呈先下降后上升的趋势,其中水胶比越小的试件下降程度越明显;钢筋电流值持续下降,其下降速率呈“慢-快-慢”的规律;微观结果与实测数据具有相同规律,锈蚀系数k的定义从锈蚀产物层面印证混凝土保护性的优劣会导致锈蚀产物存在一定差异。In view of the problem that the groundwater environment of Lanzhou Metro Line 1 contains a lot of corrosive ions,which leads to premature corrosion of reinforcement in concrete,this work simulated the groundwater environment,and carried out energized and accelerated corrosion test on three kinds of reinforced concrete specimens with different water binder ratio in which.The electrical nondestructive test was used to characterize the corrosion degree of rebars,and a microscopic test was used to verify the test results,and the corrosion laws of rebars were comprehensively analyzed.Finally,the corrosion coefficient k is derived and defined as an evaluation parameter to characterize the corrosion degree of reinforcement,and its rationality is verified.The results show that,with the aggravation of energized corrosion,the resistance value of steel bars decreases first and then increases,and the specimens of low water-binder ratio decreased more obviously;the current value of steel bar continues to drop,and the rate of decline follows the law of"slow-fast-slow";the microscopic results have the same law as the measured data.The definition of corrosion coefficient k confirms that the difference in concrete protectiveness will lead to differences in corrosion products from the perspective of corrosion products.

关 键 词：钢筋混凝土 离子侵蚀 通电腐蚀 无损检测 钢筋锈蚀 

分 类 号：TU528[建筑科学—建筑技术科学]