氯离子浓差对混凝土中钢筋锈蚀的影响

研究了存在氯离子浓差的混凝土中钢筋表面的腐蚀面积率、失重率和宏电池腐蚀特征, 并与均匀氯离子浓度相比较, 阐明了在混凝土内存在氯离子浓差作用下钢筋表面的腐蚀机理. 结果表明: 钢筋表面存在氯离子浓差相对于均匀浓度腐蚀严重, 浓差越大坑蚀越显著; 因氯离子浓差在钢筋表面形成的大阴极小阳极比小阴极大阳极腐蚀更为严重, 2种形式的宏电池腐蚀均比均匀腐蚀明显; 并且, 泌水作用加剧了混凝土内钢筋腐蚀.

Effect of concentration difference of chloride ions on the corrosion of steel bar

Corroded area rate, weight loss rate and the macro cell corrosion of rebars in concrete subjected to concentration difference of chloride ion were investigated. In order to evaluate the corrosion mechanism of rebars, the corrosion behaviour of rebars in concrete under different chloride concentration difference were contrasted with that of the concrete contaminated with uniform chlorine ion concentration. Results indicated that compared with the concrete contaminated with uniform chlorine ion concentration, the rebars corroded area are higher in concrete under different chloride ion concentration difference, and the rebars corroded area are also higher in concrete in large cathode small anode contrasted with that of the condition in large cathode small anode. Furthermore, both of rebars corroded area are more serious than uniform chlorine ion concentration.