Self-corrosion Potential,Linear Polarization Resistance measurement and Electrochemical Impedance Spectroscopy(EIS)were used to evaluate the corrosion behavior of steel rebar outside the concrete under the water. Also,electrochemical parameters of initial steel were consulted. The results of corrosion behavior of reinforcing steel between new and old showed a significant difference,such as self-corrosion potential,corrosion current density,polarization resistance of the oldew steel ratio of about 3-4,40-60 and 0.02,respectively. Based on impedance spectra in Nyquist plot reinforcing steel,with respect to the new steel rebar,the old steel had a obviously compressed capacitive arc and a significant reduction in the diameter of the semicircle in low frequency. What’s more,mass loss rate of the old steel rebar caused by corrosion was about 8%~9%,showing a positive correlation with electrochemical parameters.%通过自腐蚀电位法、线性极化法和交流阻抗谱法三种电化学方法对历时10年以上的水下混凝土钢筋的锈蚀程度进行检测，并与初始钢筋的电化学参数进行对比分析。结果表明：旧、新钢筋的电化学参数变化明显，且旧/新钢筋的自腐蚀电位比值约为3～4，腐蚀电流密度比值约为40～60，极化电阻比值约为0.02；在交流阻抗谱图中，相对于新钢筋，旧钢筋在低频区明显收缩，容抗弧半径明显减小；旧钢筋因腐蚀造成的质量损失率在8%～9%，与电化学表征参数呈现正相关。
展开▼
