杂散电流与氯离子耦合作用下对钢筋混凝土性能的影响  

Effect of Coupling Actions of Stray Currents and Chloride Ion on Performance of Reinforced Concrete

作　　者：叶瑞丰 雅菁[1] 尚静媛 刘晓铮[2] 陈倩[2] YE Ruifeng;YA Jing;SHANG Jingyuan;LIU Xiaozheng;CHEN Qian(Tianjin Chengjian University,Tianjin 300384,China;Tianjin JinBeier Architecture Engineering Test&Inspection Technology Co.,Ltd.Tianjin 300170,China)

机构地区：[1]天津城建大学,天津300384 [2]天津津贝尔建筑工程试验检测技术有限公司,天津300170

出　　处：《天津城建大学学报》2020年第5期333-336,387,共5页Journal of Tianjin Chengjian University

基　　金：天津市建委科技项目(2016.29);天津市科委企业科技特派员项目(18JCTPJC60700)

摘　　要：通过模拟杂散电流腐蚀试验,研究了杂散电流作用下Cl^-在混凝土内部的迁移特性和杂散电流与Cl^-共存条件下钢筋混凝土试块的劣化.用混凝土中Cl^-迁移深度、游离态Cl^-质量分数和Cl^-固化率,表征了电流作用下Cl^-在混凝土内部迁移特征;以钢筋混凝土试件的抗折强度和内部钢筋锈蚀电位,表征分析了钢筋混凝土试件的劣化情况.研究表明:杂散电流明显加速了混凝土内部Cl^-的扩散,Cl^-在混凝土内部的传输以电场作用的电迁移为主导;杂散电流还减弱了混凝土对Cl^-的固化能力,并且加速了Cl^-对钢筋的腐蚀速率;在电压和Cl^-的双重作用下,显著加速了混凝土内部钢筋的腐蚀速度和腐蚀程度,30V电压下通电15 d时,内掺Cl^-质量分数分别为0.05%,0.1%,0.2%时,试块内钢筋腐蚀电位分别为-344,-467,-687 mV,试块强度损失分别达到了23%,42%,51%.The deterioration process and mechanism of reinforced concrete under the double action of stray current and chloride ion were studied. The migration mechanism of chloride ions in the concrete under stray current was characterized by the migration depth of chloride ions, the concentration of free chloride ions and the chloride ions curing rate of concrete. The deterioration of reinforced concrete specimens was characterized by the flexural strength of reinforced concrete specimens and the corrosion potential of steel bars. The results showed that the stray current could significantly increase the chloride ion transfer rate in the concrete, and concrete internal electric field caused by stray current dominates the acceleration of chloride diffusion compared with free diffusion. Thus the stray current weakened the ability of concrete to bind with chloride ions. The corrosion degree of steel bars in the concrete was significantly increased under the double action of stray current and chloride ion. The specimens with chloride concentrations of 0.05%, 0.1% and 0.2% respectively lost 23%,42% and 51% of their strength,and the corrosion potential of steel bars was respectively-344,-467,-687 mV.

关 键 词：钢筋混凝土 杂散电流 氯离子固化率 钢筋腐蚀 

分 类 号：TU528[建筑科学—建筑技术科学]