硫酸盐浸泡环境下CaO-Na_(2)CO_(3)激发矿渣砂浆性能退化及机理研究  

Performance Deterioration and Mechanism of Slag Mortar Activated by CaO-Na_(2)CO_(3) in Sulfate Soaking Environment

作　　者：梁咏宁[1] 陈李全 张迎 林旭健[1] 季韬[1] LIANG Yongning;CHEN Liquan;ZHANG Ying;LIN Xujian;JI Tao(College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学土木工程学院,福州350108

出　　处：《硅酸盐通报》2022年第10期3556-3566,共11页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51708120,51878179);福建省自然科学基金(2020J01939)。

摘　　要：以Na_(2)SO_(4)和MgSO_(4)溶液为侵蚀介质,研究了在浸泡环境下CaO-Na_(2)CO_(3)激发矿渣(CNS)砂浆和普通硅酸盐水泥(OPC)砂浆经硫酸盐侵蚀前后的抗折强度、抗压强度及不同深度处的SO^(2-)_(4)浓度,结合X射线衍射(XRD)、扫描电子显微镜(SEM)、压汞法(MIP)等测试方法分析了CNS砂浆和OPC砂浆的侵蚀产物及孔结构,对比讨论了Na_(2)SO_(4)和MgSO_(4)对CNS砂浆和OPC砂浆的侵蚀机理。结果表明:CNS砂浆的水化产物主要是低Ca/Si比的水化硅铝酸钙(C-A-S-H),不存在氢氧化钙,碳酸钙的填充作用使其孔结构优于OPC砂浆,并且在相同侵蚀环境下,CNS砂浆的抗硫酸盐侵蚀能力大于OPC砂浆;MgSO_(4)侵蚀环境下CNS砂浆的侵蚀产物主要是水镁石(腐蚀后期会带动试件表面的砂浆一起剥落)和无黏聚力的水化硅铝酸镁(M-A-S-H);与Na_(2)SO_(4)相比,MgSO_(4)对CNS砂浆的腐蚀性更强。The CaO-Na_(2)CO_(3) activated slag(CNS)mortar and the ordinary Portland cement(OPC)mortar were immersed in sodium sulfate and magnesium sulfate solution respectively,and the flexural strength,compressive strength and SO^(2-)_(4) concentration in different depths of CNS and OPC mortars were studied before and after sulfate corrosion.Meanwhile,the corrosion products and pore structure of CNS and OPC mortars were analyzed by XRD,SEM and MIP.Then the corrosion mechanism of sodium sulfate and magnesium sulfate on CNS and OPC mortars was compared and discussed.The results show that the hydration products of CNS mortar are mainly calcium aluminium silicate hydrate(C-A-S-H)with low Ca/Si ratio,and there is no calcium hydroxide.The pore structure of CNS mortar is better than OPC mortar due to the filling effect of calcium carbonate,and the sulfate resistance of CNS mortar is greater than that of OPC under the same corrosion environment.The corrosion products of CNS mortar under magnesium sulfate are mainly brucite(the mortar on the specimen surface will be peeled off together in the later stage of corrosion)and non-adhesive magnesium aluminium silicate hydrate(M-A-S-H).Compared with sodium sulfate,magnesium sulfate is more corrosive to CNS mortar.

关 键 词：碱矿渣砂浆 硫酸盐 强度 抗蚀系数 侵蚀产物 孔结构 侵蚀机理 

分 类 号：TU528[建筑科学—建筑技术科学]