不同内掺氯盐耦合作用下超高性能混凝土中钢筋的电化学行为  

Passivation Behavior of Steel Bar in Ultra-High Performance Concrete under Coupling Effect of Different Internal Chloride Salts

作　　者：黄伟 陈镇东 陈荣[1] 应丰泽 黄卿维[1] 刘升 潘岩华 HUANG Wei;CHEN Zhendong;CHEN Rong;YING Fengze;HUANG Qingwei;LIU Sheng;PAN Yanhua(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China;Fuzhou Building Research Institute Co.Ltd,Fuzhou 350003,China)

机构地区：[1]福州大学土木工程学院,福州350116 [2]福州市建筑科学研究院有限公司,福州350003

出　　处：《硅酸盐学报》2023年第8期1928-1937,共10页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51878178);长江科学院开放基金(CKWV2019750/KY);福建省中科院STS计划项目(2022T3032);福州市科技计划项目(2020-S-36)。

摘　　要：采用含有不同氯盐(NaCl、CaCl_(2)和MgCl_(2))的拌合用水制备超高性能混凝土(UHPC),通过线性极化法、交流阻抗法和循环极化法测试其内部钢筋钝化期内的电化学指标,研究了不同氯盐耦合作用下UHPC中钢筋致钝行为与演化规律。结果表明:3种不同氯盐体系下,UHPC中的钢筋均能钝化;UHPC基体电阻、钢筋钝化膜电阻和钢筋电荷转移电阻均随着水化龄期的发展而不断增大;相同Cl^(-)浓度下,Ca盐引入一定程度上加大了钢筋腐蚀的可能性,而Mg盐引入一定程度上延缓了钢筋腐蚀进程;钢筋的点蚀敏感性随着Cl^(-)浓度增大而增高;高Cl^(-)浓度下,Na-Ca体系下钢筋的点蚀敏感性高于Na-Mg体系。Ultra-high performance concrete(UHPC)was prepared via mixing water containing different chloride salts(i.e.,NaCl,CaCl_(2)and MgCl_(2)).The electrochemical indexes of the internal reinforcement during passivation period were measured by linear polarization,electrochemical impedance spectroscopy and cyclic polarization.The passivation behavior and evolution of steel bars in UHPC under the coupling action of different chloride salts were investigated.The results show that the reinforcement in UHPC is able to be passivated under three different chloride salt systems.The resistances of UHPC matrix,steel passivation film and steel charge transfer increase continuously with the hydration age.At the same concentration of Cl^(-)ions,the introduction of Ca salts increases the possibility of steel corrosion to a certain extent,while the introduction of Mg salts delays the corrosion process of steel bars to some extent.The pitting corrosion sensitivity of reinforcement increases with the increment of Cl^(-)ions concentration.At a high Cl^(-)ions concentration,the pitting sensitivity of steel bars in Na-Ca system is greater than that in Na-Mg system.

关 键 词：超高性能混凝土 氯盐 钢筋 线性极化 交流阻抗 循化极化 钝化行为 

分 类 号：TQ175[化学工程—硅酸盐工业]