碳化环境下多元胶凝体系钢筋混凝土电化学特性  

Electrochemical Characteristics of Reinforced Concrete with Multiple Cementitious System in Carbonization Environment

作　　者：乔宏霞[1,2] 刘志超 路承功 付勇 QIAO Hongxia;LIU Zhichao;LU Chenggong;FU Yong(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Engineering Research Center for Disaster Prevention and Mitigation of Civil Engineering in Western China 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,甘肃兰州730050 [2]西部土木工程防灾减灾教育部工程研究中心(兰州理工大学),甘肃兰州730050

出　　处：《湖南大学学报（自然科学版）》2023年第3期110-120,共11页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(52178216,51168031)。

摘　　要：为研究不同矿物掺合料钢筋混凝土碳化后的电化学特性,利用电化学工作站定期进行无损检测,通过极化曲线、交流阻抗图谱等电化学参数对碳化循环过程中钢筋混凝土微结构的变化进行分析.采用Kramers-Kronig转换对交流阻抗数据进行验证,选用合适的等效电路进行电化学参数拟合,并采用卡方检验验证参数拟合的吻合度.研究结果表明:等效电路R(QR)(QR)可以有效地对碳化环境下钢筋混凝土的电化学阻抗谱进行拟合,等效电路拟合卡方值建议不大于10-4数量级.碳化腐蚀环境下,随着碳化周期的增加,混凝土的电阻值呈现波动增加的趋势,钢筋电阻呈现波动减小趋势;极化曲线随着碳化周期的增加整体向腐蚀电流密度增大和负电位方向移动,在49 d时钢筋锈蚀程度从大到小依次为双掺体系、单掺体系、基准体系、三掺体系,且单掺和双掺体系混凝土接近中等腐蚀状态,基准和三掺体系混凝土还处于低等腐蚀状态.不同凝胶体系下,单掺和双掺体系钢筋混凝土对碳化腐蚀环境更加敏感,三掺体系则具有最佳的抗碳化性能.In order to study the electrochemical characteristics of reinforced concrete with different mineral ad⁃mixtures after carbonization,the electrochemical workstation was used to conduct non-destructive testing regularly,and the changes of the microstructure of reinforced concrete during the carbonation cycle were analyzed by electro⁃chemical parameters such as polarization curve and AC impedance graph.Kramers-kronig conversion was used to verify the AC impedance data,and an appropriate equivalent circuit was selected to perform electrochemical param⁃eter fitting.Chi-square test was used to verify the fitting degree of parameters.The results show that the equivalent circuit R(QR)(QR)can effectively fit the electrochemical impedance spectrum of reinforced concrete in carbonized environment,and the chi-square value of equivalent circuit fitting is recommended to be less than 10-4 orders of magnitude.In the carbonization corrosion environment,with the increase of carbonization period,the resistance value of concrete shows a trend of fluctuation increase,and the resistance of steel shows a trend of fluctuation de⁃crease.Polarization curve with the increase of carbon cycle entirely moves to the corrosion current density and nega⁃tive potential direction,at 49 d,the reinforcement corrosion degree was from big to small order as the mixed system,single doped system,the benchmark system,three mixed system,and single with double mixing system concrete is nearly at medium corrosion state,while benchmarking and three concrete mixing system is still in the low state of corrosion.Under different gel systems,the single and double doped reinforced concrete is more sensitive to carbon⁃ation corrosion environment,while the triple doped reinforced concrete has the best carbonation resistance.

关 键 词：碳化 交流阻抗 多元胶凝体系 钢筋锈蚀 

分 类 号：TU528[建筑科学—建筑技术科学]