碳化与氯盐复合作用下硫氧镁胶凝材料的护筋性

Corrosion Resistance of Steel Bars of Magnesium Oxy-sulfate Cementitious Material under the Combined Action of Carbonation and Chloride Salt

关键词:  硫氧镁胶凝材料  护筋性  钢筋  碳化  氯盐  电化学阻抗

Key words:  magnesium oxy-sulfate cementitious material  corrosion resistance  steel bar  carbonation  chloride salt  electrochemical impedance

摘要:

为探究硫氧镁（MOS）胶凝材料的护筋性，研究了自然养护、碳化、氯盐以及碳化和氯盐复合作用下MOS胶凝材料的电化学阻抗、钝化和脱钝钢筋的极化曲线以及锈蚀面积率.结果表明：碳化、氯盐单独作用下，MOS胶凝材料中钢筋的阻抗均低于自然养护下的相应阻抗，且随着龄期的延长，钝化钢筋的阻抗均呈现先减小后增大的趋势，脱钝钢筋的阻抗则持续减小；碳化和氯盐复合作用下MOS胶凝材料中钢筋的锈蚀程度明显增加，碳化和氯盐复合作用对MOS胶凝材料内部钢筋锈蚀程度具有叠加效应；各种腐蚀环境中脱钝钢筋的锈蚀程度均高于钝化钢筋.

Abstract:

In order to study the corrosion resistance of magnesium oxy-sulfate （MOS） cementitious materials， the electrochemical impedance， polarization curve and corrosion area ratio of passive and de-passive steel bars were investigated under natural curing， carbonation， chloride salt and combined action of carbonation and chloride salt. The results show that the impedance of steel bars under single carbonation and chloride salt condition is lower than that in natural curing. With the increased age， the impedance of passive steel bars decreases first and then increases， while that of de-passive steel bars decreases continuously. Under the combined action of carbonation and chloride salt， the electrochemical impedance of steel bars in MOS cementitious materials is further reduced， which reflects the superposition effect of combined action of carbonization and chloride on the corrosion degree of steel bars in MOS cementitious materials. The corrosion degree of de-passive steel bars is higher than that of passive steel bars under all curing conditions.