加速碳化条件下不同养护制度对碱矿渣混凝土钢筋锈蚀的影响  

Effect of Different Curing Regimes on the Corrosion of Alkali-Activated Slag Concrete Reinforcement Under Carbonation Environment

作　　者：梁咏宁[1,2] 刘务东 赵凯 季韬[2] LIANG Yongning;LIU Wudong;ZHAO Kai;JI Tao(School of Advanced Manufacturing,Fuzhou University,Quanzhou 362251,Fujian,China;College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学先进制造学院,福建泉州362251 [2]福州大学土木工程学院,福州350108

出　　处：《材料导报》2024年第11期158-165,共8页Materials Reports

基　　金：国家自然科学基金(51708120,51878179);福建省自然科学基金(2021J02021)。

摘　　要：研究了加速碳化环境(CO_(2)浓度为20%)下,标准养护、饱和Ca(OH)_(2)溶液养护和蒸压养护对CaO+Na_(2)CO_(3)为激发剂的碱矿渣混凝土(CNC)中钢筋锈蚀的影响。结果表明,与标准养护相比,饱和Ca(OH)_(2)溶液养护不改变CNC的水化产物,但使其早期水化更加充分,因此平均孔径减小;蒸压养护使CNC水化产物由C-S-H凝胶转化为水榴石与11-?型的托勃莫来石,平均孔径和总孔隙率显著减小。在相同的加速碳化龄期下,与标准养护相比,饱和Ca(OH)_(2)溶液养护和蒸压养护的CNC碳化深度降低、CNC中钢筋发生高概率锈蚀时间延缓、钢筋失重率下降。与相同养护条件下的普通硅酸盐混凝土相比,标准养护和饱和Ca(OH)_(2)溶液养护的CNC中钢筋抗锈蚀能力远小于普通硅酸盐混凝土,而蒸压养护的CNC中钢筋抗锈蚀能力大于普通硅酸盐混凝土。In this work, the effects of standard curing, saturated Ca(OH)_(2) solution curing and autoclave curing on the corrosion of reinforcement in alkali-activated slag concrete with CaO+Na_(2)CO_(3) as the exciter (CNC) were investigated under accelerated carbonation environment (CO_(2) concentration of 20%). The results show that compared with standard curing, saturated Ca(OH)_(2) solution curing does not change the hydration products of CNC but can make the early hydration of CNC more sufficient. Therefore, the average pore size decreases. Autoclaving curing converts the hydration products of CNC from C-S-H gel into hydrogarnet and 11- type tobermorite. Therefore, the average pore size and total porosity decrease significantly. Under the same accelerated carbonization conditions, compared with standard curing, the carbonization depth of CNC decreased, the high probability corrosion time of reinforcement in CNC delayed, and the weight loss rate of reinforcement in CNC decreased both in saturated Ca(OH)_(2) solution curing and in autoclaving curing. Under the same curing conditions, the corrosion resistance of steel bars in CNC cured by standard curing and saturated Ca(OH)_(2) solution is much less than that in ordinary Portland cement concrete. The corrosion resistance of steel bars in CNC cured by autoclaving was better than that in ordinary Portland cement concrete.

关 键 词：碳化 养护制度 碱矿渣混凝土 孔结构 电化学测试 失重率 钢筋锈蚀 

分 类 号：TU528[建筑科学—建筑技术科学]