含氧量对临界氯离子浓度及钢筋锈蚀速率影响  

Effects of oxygen content on chloride threshold levels and corrosion rate of concrete reinforcing bar

作　　者：赵炜璇[1] 巴恒静[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150001

出　　处：《中国矿业大学学报》2011年第5期714-719,共6页Journal of China University of Mining & Technology

基　　金：西部交通建设科技项目(200632800003-11)

摘　　要：为了明确氧气含量对钢筋锈蚀的影响,通过对直接反应钢筋钝化膜状态信息的物理量-钢筋极化电阻的测试,研究了不同氧气含量的混凝土模拟孔隙溶液中钢筋钝化膜破坏的临界氯离子浓度及氧气含量对钢筋锈蚀速率的影响.试验结果表明:当钢筋极化电阻值小于270 kΩ.cm2并持续下降时,钢筋钝化膜开始破坏;在氧气质量浓度为10.5至8.7 mg/L的混凝土模拟孔隙溶液中,当pH值为12.5到13.4之间时,钢筋钝化膜破坏的临界氯离子浓度为Cl-与OH-浓度比值是0.1;当pH值为11.7时,钢筋钝化膜破坏临界氯离子浓度接近为零,钢筋钝化膜几乎不能保持完整.氧气含量的适当降低有效减缓了钢筋钝化膜的破坏速度,但对钝化膜破坏时的临界氯离子浓度未产生影响.Concrete reinforcing bar polarization resistance was used to determine the effects of oxygen content on chloride threshold level and re-bar corrosion rate.This parameter directly indicates the state of the passive film on the bar.Polarization resistance value below 270 kΩ·cm2 can result in a broken passivating film.Oxygen contents of 10.5 to 8.7 mg/L have a chloride threshold level of 0.1 when the pH is between 12.5 and 13.4.The passive film is imperfect when the pH is 11.7 and the critical value is nearly zero then.Appropriately reducing the oxygen content can slow the corrosion rate of the re-bar,but this has no effect on the chloride threshold level.

关 键 词：临界氯离子浓度 氧气含量 钢筋锈蚀速率 混凝土模拟孔隙溶液 极化电阻 

分 类 号：TU528[建筑科学—建筑技术科学]