ABSTRACT

Silicate ions were incorporated into a pre-treatment to mitigate corrosion in reinforcing steel bars. The efficiency of these pre-treatments was compared by testing steel samples in concrete pore simulating solutions contaminated with chloride ions. The study involved cyclic voltammetry, anodic polarisation curves and weight-loss tests following a 60-day immersion period. Surface analysis included micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrical properties of the film were analyzed by impedance spectroscopy and Mott–Schottky plots. Polarisation curves show higher pitting potentials and lower corrosion current densities when pre-treating with silicate ions. Localised attack appears after 60 days of immersion in solutions containing chloride ions, but weight loss is reduced by 75% for coupons pre-treated in silicate solutions. XPS and Raman spectra indicate that the presence of silicate ions affects the composition of the passive film and the corrosion products. The results show that pre-treatments in silicate solutions are effective to minimise steel corrosion in aggressive environments.

摘要

硅酸盐离子被纳入预处理以减轻钢筋腐蚀。通过在受氯离子污染的混凝土孔隙模拟溶液中测试钢样品来比较这些预处理的效率。该研究涉及循环伏安法、阳极极化曲线和 60 天浸泡期后的重量损失测试。表面分析包括显微拉曼光谱和 X 射线光电子能谱 (XPS)。通过阻抗谱和莫特-肖特基图分析薄膜的电性能。当用硅酸盐离子进行预处理时，极化曲线显示出更高的点蚀电位和更低的腐蚀电流密度。在含有氯离子的溶液中浸泡 60 天后出现局部攻击，但在硅酸盐溶液中预处理的试样重量损失减少了 75%。XPS 和拉曼光谱表明硅酸盐离子的存在会影响钝化膜和腐蚀产物的组成。结果表明，在硅酸盐溶液中进行预处理可以有效地减少腐蚀性环境中的钢腐蚀。