珊瑚混凝土中钢筋涂层的防护试验研究

Experimental study on protection of steel bar coating in coral concrete

珊瑚混凝土结构除了提高混凝土自身的耐久性外,采用附加防腐蚀措施是确保珊瑚混凝土结构长期服役的有效手段。通过对C30强度珊瑚混凝土开展半浸泡外加电流加速锈蚀试验,研究了珊瑚混凝土中环氧树脂涂层的防护性能,建立了涂层钢筋锈蚀率与锈胀裂缝宽度的关系模型,对比分析了涂层钢筋和普通钢筋的极化曲线,并结合微观阐述了钢筋涂层的防护机理。试验结果表明,采用半浸泡法可以较好地模拟涂层钢筋在海洋环境下的锈蚀情况,涂层钢筋锈蚀率与裂缝宽度呈正比关系;氯盐环境中环氧树脂涂层电化学阻抗随时间先减小后增大,后又继续减小。环氧涂层作为珊瑚混凝土中的钢筋的长期耐蚀涂层材料,具有较好的防护性能。

In addition to improving the durability of coral concrete structure,additional anti-corrosion measures are an effective means to ensure the long-term service of coral concrete structure.Through the accelerated corrosion test of C30 coral concrete with half immersion and applied current,the protective performance of epoxy resin coating in coral concrete is studied,the relationship model between corrosion rate of coated steel bar and the width of corrosion expansion crack is established,the polarization curves of coated steel bar and ordinary steel bar are compared and analyzed,and the protective mechanism of steel bar coating is expounded combined with microcosmic analysis.The results show that the semi immersion method can simulate the corrosion of coated steel bars in marine environment,and the corrosion rate of coated steel bars is proportional to the crack width.The electrochemical impedance of epoxy coating in chloride environment first decreases and then increases with time,and then continues to decrease.As a long-term corrosion-resistant coating material for steel bars in coral concrete,epoxy coating has good protection performance.