电极工作面积和孔隙液pH值对钢筋脱钝临界氯离子浓度的影响  

Influence of Working Area of Electrode and pH Value of Pore Solution on Critical Chloride Concentration for Steel Bar Depassivation

作　　者：卢金马 黄俊铭 余波[1,2,3] 张正鑫 万伟伟 LU Jinma;HUANG Junming;YU Bo;ZHANG Zhengxin;WAN Weiwei(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Engineering Disaster Prevention and Structural Safety of Ministry of Education,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Disaster Prevention and Engineering Safety,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004 [3]广西大学广西防灾减灾与工程安全重点实验室,广西南宁530004

出　　处：《建筑材料学报》2021年第5期994-1001,共8页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51668008,51738004,51678165);广西杰出青年科学基金资助项目(2019GXNSFFA245004);广西自然科学基金资助项目(2018GXNSFAA281344);广西研究生教育创新计划资助项目(YCSW2021026)。

摘　　要：基于模拟混凝土孔隙液中的钢筋脱钝试验,揭示了钢筋电极的工作面积和模拟混凝土孔隙液的pH值对钢筋脱钝过程中开路电位、极化电阻和腐蚀电流密度的影响规律,确定了不同钢筋电极工作面积和pH值条件下钢筋脱钝的临界氯离子浓度,分别建立了钢筋电极工作面积和模拟混凝土孔隙液pH值与钢筋脱钝临界氯离子浓度之间的定量关系.结果表明:随着钢筋电极工作面积的增大,钢筋脱钝的临界氯离子浓度降低;随着模拟混凝土孔隙液pH值的增加,以自由氯离子浓度[Cl^(-)]表征的临界氯离子浓度增加,而以[Cl^(-)]/[OH^(-)]表征的临界氯离子浓度降低;与开路电位和极化电阻相比,钢筋脱钝过程中腐蚀电流密度的突变点更加明显.Based on depassivation experiments of steel bar in simulated concrete pore solution,the influences of working area for steel electrode and pH value for simulated concrete solution on open-circuit potential,polarization resistance and corrosion current density during depassivation process were investigated.The critical chloride concentration of steel bar under different conditions of working areas and pH values were determined.The quantitative relationship between the critical chloride concentration and the working area as well as pH value were established respectively.The results show that the critical chloride concentration decreases with the increase of working area of steel electrodes.The critical chloride concentration in terms of free chloride ion concentration[Cl^(-)]increases with the increase of pH value for simulated concrete pore solution,while the critical chloride concentration in terms of[Cl^(-)]/[OH^(-)]decreases with the increase of pH value for simulated concrete pore solution.Comparing with open-circuit potential and polarization resistance,the inflection point of corrosion current density is more obvious during the depassivation process of steel bar.

关 键 词：模拟混凝土孔隙液 钢筋电极 工作面积 PH值 临界氯离子浓度 

分 类 号：TU528.571[建筑科学—建筑技术科学]