新型复配阻锈剂在混凝土模拟液和试块中对钢筋锈蚀的抑制

Inhibition Effect of a New Composite Organic Inhibitor on Corrosion of Steel Rebar in Simulated Concrete Solution or Inside Mortar Specimen

利用半电池腐蚀电位、线性极化和电化学交流阻抗技术,分别在混凝土模拟液和干湿循环加速腐蚀混凝土试块中,研究了新型复配有机阻锈剂(IMC-16)对钢筋锈蚀行为的影响,并将其与常规Ca(NO2)2阻锈性能相对比。结果表明,无论在混凝土模拟液中还是在混凝土试块中,空白条件下,随实验时间延长钢筋电极腐蚀电位不断下降,腐蚀电流密度迅速升高,表明在Cl-侵蚀性作用下钢筋表面钝性遭到破坏,并发生严重局部腐蚀;而添加IMC-16阻锈剂后,钢筋电极腐蚀电位升高,阻抗模值增大,腐蚀电流密度与双电层电容显著下降,表明钢筋的锈蚀得到很好的控制。复配阻锈剂对Cl-诱导的钢筋局部腐蚀具有优良的抑制效果,并可有效延缓钢筋的起始锈蚀时间。干湿循环实验结果进一步表明,实验初期Ca(NO2)2虽可较好抑制钢筋的锈蚀,但其后期阻锈性能却明显下降;而复配阻锈剂在实验初期阻锈性能虽不明显,但相同使用浓度下,其后期阻锈效果及稳定性却明显优于Ca(NO2)2。

The inhibition effect of a new composite organic inhibitor（named IMC-16） on the corrosion of steel rebar in simulated concrete solutions or inside mortar specimens was investigated by means of half-cell corrosion potential measurement, linear polarization measurement and electrochemical impendence spectroscopy respectively. For the comparison, the inhibition effect of a conventional inhibitor Ca（NO2）2 was also presented. Results indicate that whether in simulated concrete solutions or in-side mortar specimens,for the case of blank, the corrosion potentials of steel rebar electrodes gradually reduced, while the corrosion current densities significantly increased, indicating that the passivity of steel rebar was deteriorated and the localized corrosion initiated on the surface of steel rebar electrodes due to the aggressive effect of chloride ions. However, after the addition of IMC-16 inhibitor, the corrosion potentials and the impedance modulus of steel rebar electrodes were obviously increased, the corrosion current densities and double layer capacitances largely decreased in comparison with those of blank, which reveal that the corrosion of steel rebar was well controlled, the composite organic inhibitor had excellent inhibition effect for the chloride-induced corrosion, and the onset time of steel rebar corrosion was effectively delayed. Dry and wet cycle experiments further show that Ca（NO2）2 could retard the steel rebar corrosion at the early stage of tests, but its inhibition performance was gradually decreased with the process of experiments. In comparison with Ca（NO2）2, although the inhibition effect of IMC-16 inhibitor was not enough to prevent the steel rebar from corrosion at the early stage of tests, but its inhibition effect and stability were much better than those of Ca（NO2）2 at the same concentration for long term.