混凝土结构中钢筋初始表面状态对其腐蚀行为的影响

Effect of initial surface condition on the corrosion behavior of reinforcing steel in concrete structure

建立了宏电池腐蚀回路,通过分析不同初始表面状态的钢筋在无氯盐试块和有氯盐试块中的腐蚀电位、微电池腐蚀速度、极化曲线和宏电池腐蚀速度,研究了钢筋初始表面状态对其腐蚀行为的影响。结果表明,与全裸抛光表面相比,原氧化皮表面或初始锈蚀表面对改善钢筋的腐蚀电位起积极作用。锈蚀表面钢筋的微电池腐蚀速度较大且随着初始锈蚀程度的增加而增大。与初始锈蚀表面相比,原氧化皮表面能削弱钢筋的微电池腐蚀,但对其宏电池腐蚀有不利的影响。

The influence of initial surface conditions on the corrosion behavior of reinforcing steel embedded in chloride-free and chloride-contaminated mortar was investigated by analyzing the half-cell potential, micro-cell corrosion rate, macro-cell corrosion rate and anodic/cathodic polarization curves. The results indicated that the existing oxides on the surface of the scaled or pre-rusted steels played a positive role in improving the half-cell potential. The micro-cell corrosion rate of rusted steels was much higher than that of polished and scaled steels, and increased with the increasing of pre-rusting degrees. The scaled surface could reduce the micro-cell corrosion of steel, but had a negative impact on the macro-cell corrosion of steel.