不同地聚物砂浆抗硫酸盐侵蚀性能及其机理分析  

Sulfate Resistance and Mechanism Analysis of Different Geopolymer Mortars

作　　者：郑毅 王爱国[1] 刘开伟[1] 朱颖灿 王星尧 ZHENG Yi;WANG Aiguo;LIU Kaiwei;ZHU Yingcan;WANG Xingyao(Anhui Key Laboratory of Advanced Building Materials,Anhui Jianzhu University,Hefei 230022,China;Centre for Future Materials,University of Southern Queensland,Toowoomba 4350,Australia)

机构地区：[1]安徽建筑大学安徽省先进建筑材料重点实验室,安徽合肥230022 [2]南昆士兰大学未来材料中心,昆士兰图文巴4350

出　　处：《建筑材料学报》2021年第6期1224-1233,共10页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51778003,52172013);安徽省重点研究与开发计划项目(202004b11020033);安徽建筑大学科研储备库培育项目(2021XMK02)。

摘　　要：将不同地聚物砂浆分别浸泡在5%MgSO_(4)和5%(NH_(4))2SO_(4)溶液中侵蚀120 d,以探究侵蚀离子和浸泡方式对地聚物砂浆抗硫酸盐侵蚀性能的影响,并分析了其侵蚀机理.结果表明:在MgSO_(4)与(NH_(4))2 SO_(4)溶液中全浸泡120 d后,偏高岭土基地聚物砂浆(MK‐M)与偏高岭土-矿渣基地聚物砂浆(MK+SG‐M)仍能维持稳定结构,其抗压抗蚀系数均大于0.80,矿渣基地聚物砂浆(SG‐M)抗压抗蚀系数分别为0.73和0.50,粉煤灰-矿渣基地聚物砂浆(FA+SG‐M)的抗压抗蚀系数分别为0.72和0.68;SG‐M和FA+SG‐M半浸泡在5%MgSO_(4)溶液120 d后,其浸泡区抗压强度损失明显大于干燥区;SG‐M与FA+SG‐M在不同硫酸盐环境下生成石膏等侵蚀产物,加剧了砂浆的结构破坏与性能劣化;不同地聚物抗硫酸盐侵蚀性能差异明显,可能源自于生成产物的种类和结构不同.偏高岭土基与偏高岭土-矿渣基地聚物的主要产物是水化硅铝酸钠(N‐A‐S‐H)凝胶,该凝胶结构稳定,硫酸盐侵蚀过程中主要是侵蚀阳离子对产物结构的影响;矿渣基与粉煤灰-矿渣基地聚物主要产物是水化硅铝酸钙(C‐A‐S‐H)凝胶,硫酸盐侵蚀机理类似于传统硅酸盐水泥硫酸盐侵蚀机理.Different types of geopolymer mortars were prepared and immersed in 5%MgSO_(4) and 5%(NH_(4))2 SO_(4) solutions for 120 days to measure the sulfate attack.The influence of erosin ions and immersion method on the sulfate resistance of geopolymer mortars were investigated,and the degradation mechanism was analyzed.The results show that metakaolin⁃based geopolymer mortars(MK⁃M)and metakaolin⁃slag⁃based geopolymer mortars(MK+SG⁃M)maintained the stable structure after completely immersed in MgSO_(4) and(NH_(4))2SO_(4) solutions for 120 d,and both of the compression and corrosion resistance coefficients are greater than 0.80.The compression and anti⁃corrosion coefficients of slag⁃based geopolymer mortar(SG⁃M)is 0.73 and 0.50,respectively.The compression and anti⁃corrosion coefficients of fly ash⁃slag⁃based geopolymer mortar(FA+SG⁃M)is 0.72 and 0.68,respectively.After SG⁃M and FA+SG⁃M are partially immersed in 5%MgSO_(4) solution for 120 d,the loss of compressive strength in the immersion zone is obvious compared with that in the dry zone.Gypsum and other reaction products are formed in SG⁃M and FA+SG⁃M under different sulfate and partial⁃immersion attack,which accelerate the structural degradation.Sulfate resistance of these geopolymers is obviously different,because of the different types and structures of the products formed in the samples.N⁃A⁃S⁃H gels are the main products formed in metakaolin⁃based geopolymer and metakaolin+slag⁃based geopolymer.The structure of N⁃A⁃S⁃H gels is stable under sulfate attack.Aggressive cations degrade the structure during the sulfate attack.The main reaction products formed in the slag⁃based geopolymer and fly ash+slag⁃based geopolymer are C⁃A⁃S⁃H gel,and its sulfate degradation mechanism is similar to that of traditional Portland cement.

关 键 词：地聚物 硅铝质原料 硫酸盐侵蚀 浸泡方式 

分 类 号：TU501[建筑科学—建筑技术科学]