阳离子类型对粉煤灰混凝土中钢筋锈蚀行为的影响

Effect of cation type on corrosion behavior of steel reinforcement in fly ash concrete

选用4种常见化冰盐KCl,NaCl,CaCl2和MgCl2,应用半电池电位法、电化学阻抗谱法等研究阳离子类型对粉煤灰混凝土中钢筋腐蚀行为的影响,利用自腐蚀电位和腐蚀电流密度分别判定钢筋的起始腐蚀。结果表明:阳离子类型对钢筋的腐蚀行为有明显影响;粉煤灰能够有效降低钢筋受氯盐腐蚀的风险。与NaCl和KCl相比,MgCl2和CaCl2能够明显缩短钢筋起始腐蚀阶段寿命,加快钢筋的腐蚀速度。

Four kinds of chloride deicing salt,KCl,NaCl,CaCl2,and MgCl2,were chosen to study the corrosion of steel reinforcement.The half-cell potential and electrochemical impedance spectroscopy methods were used to investigate the effect of cation type on the corrosion behavior of steel reinforcement in fly ash concrete.Based on the open-circuit potential and the corrosion current density,the onset of pitting corrosion was detected by electrochemical impedance spectra.The results show that the cation type has a significant influence on the corrosion of steel reinforcement,and fly ash can effectively reduce the risk of chloride-induced corrosion.In addition,compared with NaCl and KCl,MgCl2 and CaCl2 can obviously shorten the service lifetime of steel reinforcement upon the onset of pitting corrosion and accelerate the corrosion steel reinforcement.