Cl^-与SO_4^(2-)共同作用下开裂混凝土中钢筋的电化学特征  

Electrochemical characteristics of reinforcement in cracked concrete under collective effect of chloride and sulfate

作　　者：荀永宁 冯泽慧 李威威[2] 王曙光[2] XUN Yongning;FENG Zehui;LI Weiwei;WANG Shuguang(Jiangsu Bosen Archtectural Design Co.Ltd.,Wuxi 214072,China;College of CivilEngineering,Nanjing Tech University,Nanjing 211800,China)

机构地区：[1]江苏博森建筑设计有限公司,江苏无锡214072 [2]南京工业大学土木工程学院,江苏南京211800

出　　处：《南京工业大学学报（自然科学版）》2019年第3期333-337,共5页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家重点基础研究发展计划(2011CB013801);国家自然科学基金(51308285);江苏省研究生科研创新计划(CXZZ13_0440)

摘　　要：在地下结构和沿海结构的工作环境中常存在着Cl^-、SO_4^(2-)等,且混凝土结构受到收缩、徐变、荷载等的影响,常处于带裂缝的工作状态,此类结构中钢筋的锈蚀过程比较复杂。本文设计了耐久性试验,采用预裂法制作开裂混凝土试件,利用腐蚀电位、线性极化法、动电位极化法和电化学阻抗谱法研究了Cl^-和不同SO_4^(2-)浓度混合溶液下开裂混凝土内钢筋的电化学特征。结果表明:在Cl^-和SO_4^(2-)混合溶液中,当SO_4^(2-)浓度增大时,开裂混凝土内钢筋的腐蚀电位随之增大,钢筋锈蚀的概率随之减小,钢筋的腐蚀电流密度随之降低;SO_4^(2-)抑制了开裂混凝土内钢筋的锈蚀进程。A large number of ions such as chloride ions,sulfate ions usually exist in service environment of underground concrete structure and coastal concrete structure.Concrete structures usually work with cracks,which were induced by the concrete shrinkage,concrete creep and load.Thus,the rebar corrosion process is more complex in such structures.In this paper,the durability test was designed and cracked concrete specimens were prepared by pre-splitting method.The effects of chloride ion interactive with different sulfate ion concentration on rebar corrosion process in cracked concrete were studied by chemical methods,such as corrosion potential,linear polarization method,potentio-dynamic polarization method and electrochemical impedance spectroscopy.The results showed that the corrosion potential of the steel in the cracked concrete increased with the increase of the sulfate ions concentration,and the probability of the corrosion of the steel decreased with the increase of the concentration of sulfate ions.The corrosion current density of the reinforced concrete in the cracked concrete was gradually reduced when the sulfate ions concentration increased.The sulfate ion inhibited the corrosion process of the reinforced concrete in the cracked concrete.

关 键 词：开裂混凝土 SO4^2- 多因素共同作用 钢筋锈蚀 

分 类 号：TU513[建筑科学—建筑技术科学]