阻锈剂对海洋环境下混凝土中钢筋腐蚀影响的电化学研究

Electrochemical study on effect of rust inhibitors on corrosion of reinforcing bar in concrete in marine environment

为提高海洋环境下钢筋混凝土结构的耐腐蚀性能,通过采用线性极化(LPR)与交流阻抗(EIS)2种电化学方法分别测试得到了经模拟海水侵蚀后混凝土中钢筋的极化曲线与阻抗复平面图,从而得到腐蚀电位、极化电阻、混凝土电阻、电荷迁移电阻等关键电化学参数,以此分析并讨论了4种不同阻锈机理的新型阻锈剂(SBT■-KLJ(Ⅵ)疏水化合孔栓物、SBT■-RMA(Ⅱ)混凝土高效防腐剂、SBT■-ZX(Ⅴ)复合氨基醇阻锈剂与改性亚硝酸钙阻锈剂)对混凝土中钢筋耐腐蚀性能的影响规律.结果表明:混凝土中钢筋的腐蚀过程分为过渡期与稳定期2个阶段,不同阶段呈现不同的电化学特征;SBT■-RMA(Ⅱ)混凝土高效防腐剂对钢筋混凝土结构耐腐蚀性能的提升效果显著,SBT■-ZX(Ⅴ)复合氨基醇阻锈剂与SBT■-KLJ(Ⅵ)疏水化合孔栓物的提升效果较好,而改性亚硝酸钙阻锈剂的提升效果一般.

To improve the corrosion resistance of reinforced concrete structures in the marine environment, the linear polarization resistance(LPR) and the electrochemical impedance spectroscopy(EIS) were taken to test the polarization curves and impedance complex plans of the steel bars in concrete after simulated seawater erosion. The key electrochemical parameters such as corrosion potential, polarization resistance, concrete resistance, and charge transfer resistance were obtained, the influence of four new rust inhibitors on the corrosion resistance of steel in concrete was analyzed and discussed. The results show that the corrosion process of steel in concrete can be divided into two stages with different electrochemical characteristics, including transition period and stable period. SBT■-RMA(Ⅱ) salt crystallization inhibitor has a significant improvement in the corrosion resistance of reinforced concrete structures, and SBT■-ZX(Ⅴ) composite amino-alcohol has a good improvement as well as SBT■-KLJ(Ⅵ) hydrophobic pore-blocking agent, while the modified calcium nitrite has a little improvement.