混凝土中钢筋的腐蚀机理与腐蚀速率控制研究

采用极化曲线和电化学阻抗谱法,研究了混凝土中钢筋在不同试验条件下的腐蚀机理及其腐蚀速率计算方法.结果表明:在自然腐蚀条件下,钢筋腐蚀反应过程受阳极反应控制,采用修正的双向线性极化电阻公式计算其腐蚀速率.然而在通电加速腐蚀条件下,钢筋的腐蚀反应过程受电化学和浓差极化混合控制,通过拟合弱极化曲线可以得到相对准确的极化电阻....

The Steel Corrosion Mechanism and Corrosion Rate Control in Concrete

The corrosion control mechanism and corrosion rate calculation method of rebar in concrete exposed to different test conditions were studied using polarization curve and electrochemical impedance spectroscopy. The results show that, under natural corrosion condition, the corrosion reaction process of rebar was controlled by the anodic reaction. The corrosion rate can be effectively calculated utilizing a modificative equation used to calculate the bidirectional linear polarization resistance. However, under accelerated corrosion condition, the corrosion reaction process of rebar was controlled by combined mechanism of electrochemical and concentration polarization. The polarization resistance with a relatively high accuracy can be obtained by fitting the weak polarization curve. The research results provide a reference for the judgment of corrosion mechanism and the control of corrosion rate of steel reinforcement in concrete structures.