混凝土保护涂层抗氯离子渗透性研究  

RESISTANCE TO CHLORIDE ION PERMEATION OF REINFORCED CONCRETE WITH PROTECTIVE OVERLAYER COATINGS

作　　者：刘儒平[1] 萧以德[1] 蒋荃[2] 周学杰[1] 刘玉军[2] 郑鹏华[1] 

机构地区：[1]武汉材料保护研究所,武汉430030 [2]中国建筑材料科学研究院,北京100024

出　　处：《腐蚀科学与防护技术》2006年第2期83-86,共4页Corrosion Science and Protection Technology

基　　金：国家自然科学基金资助项目(50499331-9)〔50471110〕

摘　　要：在NaCl溶液中对混凝土保护涂层进行干/湿循环加速腐蚀实验,用电化学循环极化法和高压渗水法对混凝土保护涂层的防护效果进行了研究,并将两种方法研究结果进行对比.结果表明:氯盐环境中,混凝土保护涂层可以有效提高混凝土的抗渗性,降低氯盐对钢筋的腐蚀破坏;循环极化测试法可用于研究钢筋钝化膜的溶解特性和钢筋的锈蚀趋势.The corrosion behavior of reinforcing steel bars depends on the protective oxide scale formed on its surface. Chloride ions degrade the oxide and cause localized breakdown and pitting. Chloride-induced corrosion of reinforcing steel bars in concrete begins when the chloride content of concrete immediately next to the rebar reaches a critical threshold value. In the experiment, extensive studies have been performed on the reintorced concrete with protective coatings in terms of resistance to chloride ions permeation of the coated concrete. After a laboratory accelerated cyclic dry-wet test, the tested reinforced concretes without and with coatings were then evaluated with cycle polarization in NaCl solution to assess the pitting tendencies of reinforcing steel bars. The penetration test of high pressure water was used to study the influence of concrete protective coatings on the penetration of reinforced concrete in comparison with those of cyclic polarization. The results showed that concrete protective coatings could reduce chloride ion penetration significantly and the corrosion of reinforced bars. To con- clude, the applicability of cyclic polarization might be used to examine the dissolution characteristics of oxide scale on reinforced bars and the pitting tendency of reinforced bars in the environment containing chloride ion. It is hoped that this study will eventually lead to a better understanding of the role of chloride ion in pitting corrosion of the reinforced bar.

关 键 词：混凝土保护涂层 氯离子渗透 孔蚀环状极化曲线 

分 类 号：TB304[一般工业技术—材料科学与工程]