摘要
采用氢氧化钠激发矿渣活性,研究钢筋矿渣砂浆在碳化环境中的pH值、碳化深度、抗折强度和钢筋锈蚀发展与氢氧化钠激发剂掺量的关系。研究结果表明:氢氧化钠激发的矿渣砂浆碳化前pH值在13以上,碳化后pH值下降,下降幅度随着氢氧化钠掺量的减少而略微增大。矿渣砂浆的碳化深度随着氢氧化钠掺量增加而下降。在标准养护环境中,预埋在矿渣砂浆中的钢筋自腐蚀电位均正于-200mV,表明钢筋均能形成稳定钝化膜。碳化环境下钢筋自腐蚀电位逐渐变负,最后均低于-350mV,表明钢筋都发生锈蚀,但锈蚀出现的时间随着氢氧化钠掺量的增加而延迟。碳化会导致氢氧化钠激发的矿渣砂浆抗折强度下降。当氢氧化钠掺量为矿渣质量分数的6%时,矿渣砂浆碳化前及碳化后的抗折强度相对最高。
Carbonization behavior of slag mortars activated by different dosage of NaOH was researched.The effect of carbonization on reinforced bars which embedded in NaOH-slag mortars was also examined.The results indicate that before carbonization,the pH value of NaOH-slag mortar is above 13 and the pH value decrease after carbonization.The decrease range is enlarged with the NaOH dosage reducing.Carbonization depth of NaOH-slag mortar abates with the dosage of NaOH increasing.During standard curing,the self corrosion potential of reinforced bars which embedded in NaOH-slag mortars are all positive to-200 mV,indicating reinforced bars are capable of forming stable passivation film in NaOH-slag mortars.The self corrosion potential of reinforced bars are all negative to-300 mV with the time of carbonization,but the occurrence of corrosion delays as the NaOH dosage increasing.The dosage of NaOH has effect on flexural strength of slag mortar no matter whether carbonization or not.After carbonization,flexural strength of NaOH-slag mortars all decline.When the dosage of NaOH is 6%（slag mass fration）,flexural strength of slag mortar is high relatively.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2015年第5期702-706,696,共6页
Journal of Materials Science and Engineering
基金
国家自然基金资助项目(51278167)
江苏省住房与城乡建设部基金资助项目(2013-k3-1)
南京工程学院大学生科技创新资助项目(N20150903)
关键词
碱激发矿渣
PH值
碳化深度
钢筋锈蚀
alkali-activated-slag
pH value
carbonization depth
reinforced bar corrosion
