摘要
针对氯盐与硫酸盐耦合环境下的钢筋混凝土腐蚀问题,以水泥净浆层代替混凝土保护层,设计制作了系列水泥净浆-钢筋试件,开展了单一氯盐及氯盐-硫酸盐复合溶液中各试件的Tafel极化、电化学阻抗谱(EIS)及微观形貌测试,分析了开路电位、腐蚀电流密度、双电层电容和弥散指数等电化学参数随腐蚀时间的变化规律,并评估了硫酸盐含量对氯盐环境下钢筋腐蚀进程及腐蚀程度的影响。结果表明,连续不间断的电化学测试及相应的参数拟合能准确表征钢筋的腐蚀动力学过程,且Tafel极化曲线法与EIS所得结论一致;硫酸根离子会造成混凝土保护层膨胀开裂,加快氯离子在混凝土中的传输速率,从而在加快钢筋混凝土腐蚀进程的同时也加剧了混凝土内钢筋的腐蚀程度。
According to the corrosion of reinforced concrete under the coupling action of chloride and sulfate attacks,some cement paste-steel specimens have been prepared,which were used to replace reinforced concrete,in order to electrochemically and microscopically measuring by Tafel polarization,EIS and SEM.The variation of electrochemical parameters-such as open circuit potential,corrosion current density,double-layer capacitor and dispersion index-with the corrosion time have been analyzed.Then,the influence of sulfate contents on corrosion process and corrosion degree of steel in chloride salt environment were evaluated.Results show that,continuous electrochemical testing with parameter fitting can accurately characterize the corrosion kinetics of steel in concrete,and the testing results of Tafel polarization were consistent with EIS.Furthermore,sulfate ions caused expansion and cracking of concrete protective layer so that the transmission rate of chloride ions in concrete has been speeded up,which accelerated the corrosion process of reinforced concrete and also increased the corrosion degree of steel bars in concrete.
作者
邹帅
左晓宝
汤玉娟
殷光吉
ZOU Shuai;ZUO Xiaobao;TANG Yujuan;YIN Guangji(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China)
出处
《混凝土》
CAS
北大核心
2019年第11期23-28,共6页
Concrete
基金
国家自然科学基金（51778297）
