胶凝材料组成对钢筋混凝土耐久性的影响  

Influence of Cementitious Material Composition on Durability of Reinforced Concrete

作　　者：范志宏[1,2] 黎鹏平 苏达根[1] 王胜年 

机构地区：[1]华南理工大学特种功能材料教育部重点实验室,广东广州510640 [2]水工构造物耐久性技术交通行业重点实验室,广东广州510230

出　　处：《华南理工大学学报（自然科学版）》2012年第4期85-89,94,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家“十二五”科技支撑计划项目(2011BAG07B04)

摘　　要：利用电化学阻抗法和压汞法等研究了外渗氯盐条件下胶凝材料组成对钢筋混凝土耐久性的影响,结果表明:随胶凝材料中粉煤灰或矿渣含量的提高,钢筋混凝土耐久性、混凝土电阻率和钢筋电荷转移电阻先增加后减少,钢筋腐蚀速率则先减少后增加;氯离子临界浓度随钢筋周围溶解氧含量的提高及Ca(OH)2含量的降低而降低;掺合料取代部分水泥后提高了混凝土的致密性,增大了电荷转移电阻,提高了钝化膜的稳定性,同时会降低混凝土内的Ca(OH)2含量,引起氯离子临界浓度下降.This paper deals with the influences of cementitious material composition on the durability of reinforced concrete with extravasated chloride via electrochemical impedance spectroscopy and MIP test. The results show that, with the increases of fly ash or slag content in the cementitious material, the durability, the resistivity and the charge transfer resistance of reinforced concrete all increase first and then decrease, while the corrosion rate of steel varies in an opposite trend; and that the chloride threshold concentration decreases with the increase of dissolved oxygen content and with the decrease of Ca（OH）2 content around the steel. Moreover, it is found that, when ce- ment is partially substituted with fly ash or slag, the density of the concrete increases, which results in the increase of charge transfer resistance, the improvement of stability of the passive film, the decrease of Ca（OH） 2 content, and, finally, the decrease of the chloride threshold concentration.

关 键 词：钢筋混凝土 胶凝材料 耐久性 外渗氯离子 钢筋腐蚀速率 氯离子 临界浓度 

分 类 号：TU528.44[建筑科学—建筑技术科学] TQ174[化学工程—陶瓷工业]