高级脂肪酸对混凝土中钢筋锈蚀抑制作用机理研究

Study on mechanism of steel fiber anti-corrosion in reinforced concrete by higher fatty acids

通过毛细吸水试验和氯离子电迁移试验,研究了高级脂肪酸对混凝土抗渗性及抗氯离子渗透性能的影响。通过电化学测试和X射线衍射测试,分析了高级脂肪酸对混凝土中钢筋锈蚀抑制作用机理。研究结果表明:高级脂肪酸可提高混凝土的孔隙电阻及钢筋电极反应的电荷转移电阻,降低腐蚀电流密度,从而抑制钢筋的锈蚀趋势。同时,高级脂肪酸可与水泥水化产物发生反应,生成表面张力较小的脂肪酸盐,降低水分及侵蚀性离子向混凝土中的迁移渗透速率。

In this work,the effect of higher fatty acid on the impermeability and resistance to chloride ion permeation of concrete was studied through capillary water absorption test and chloride ion electromigration test.The inhibitory mechanism of higher fatty acids on corrosion of fibers in concrete was analyzed by electrochemical tests and X-ray diffraction tests.The results of the study indicate that higher fatty acids can increase the pore resistance of the concrete and the charge transfer resistance of the reaction of the steel fibers,reduce the corrosion current density,and thus inhibit the corrosion tendency of the steel fibers.At the same time,higher fatty acids can react with cement hydration products and generate fatty acid salts with lower surface tension and reduce the migration infiltration rate of water and aggressive ions into concrete.