偏高岭土-矿渣基地聚物与花岗岩骨料界面的分布特性及影响因素  

Distribution and factors of interfacial transition zone between metakaolin-slag-based geopolymer and granite aggregate

作　　者：崔潮 肖斌[1] 张建仁[2] 蔡春声[3] 刘扬[2] 彭晖[2] 

机构地区：[1]长沙理工大学交通基础设施安全风险管理行业重点实验室,长沙410114 [2]长沙理工大学桥梁工程安全控制教育部重点实验室,长沙410114 [3]路易斯安那州立大学土木与环境工程系,路易斯安那州美国70803

出　　处：《复合材料学报》2017年第11期2605-2613,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51578078);国家"973"计划(2015CB057701);长沙市科技计划(K1508020-31);长沙理工大学土木工程优势特色重点学科创新性项目(16ZDXK10);长沙理工大学交通基础设施安全风险管理行业重点实验室开放基金(16BCX06);湖南省研究生科研创新项目(CX2016B388)

摘　　要：以碱激发偏高岭土-矿渣作为胶凝材料、花岗岩为骨料制备地聚物混凝土,通过扫描电镜SEM-EDS及显微硬度分析研究地聚物与骨料的界面粘结区的微观结构、分布,以及液固比和骨料尺寸对地聚物-骨料界面的影响。研究结果表明,在地聚物与骨料的界面区域存在界面过渡区(ITZ),包含了以N-A-S-H凝胶为主的固相和收缩裂缝,化学组分与地聚物凝胶有较大不同。界面过渡区沿骨料周围不同位置表现出明显的分布不均匀特性,骨料下缘处的界面过渡区的微观结构和硬度都显著更差。随着液固比及骨料半径的增大,其分布的不均匀性增加:骨料下界面ITZ中的裂缝宽度增大,N-A-S-H凝胶厚度减小且强度降低;但配比及骨料尺寸对骨料上界面及侧界面的ITZ影响并不显著。骨料下界面ITZ应是偏高岭土-矿渣基地聚物混凝土的薄弱区域。The alkali-activated metakaolin ground granulated blast fumace slag（GGBFS）and granite were used as cementitious material and aggregate,respectively,to prepare geopolymer concrete.And SEM-EDS and microhard-ness test were conducted to investigate the microstructure,distribution around the aggregate surface,and mechani-cal properties of the bond zone between geopolymer paste and aggregate.Test results indicate that an interfacial transition zone （ITZ）exists in the bond zone between geopolymer gel and aggregates.The ITZ includes crack and N-A-S-H gel,whose chemical composition is different from geopolymer gel.The distribution of ITZ around aggre-gate surface is not uniform,since the ITZ near soffit of aggregate has a weaker microstructure and a lower hardness than those on upper and side surfaces of aggregate.With the increase in the liquid/solid ratio and the dimension of aggregate,the width of crack in ITZ at aggregate soffit increases and the thickness of N-A-S-H gel decreases,mean-while changes of mixture and aggregate dimension have no obvious effect on the microstructure and the strength ofITZ at upper and side interface around aggregate,which indicates a significant inhomogeneity.It can be concluded from test results that the interface between geopolymer gel and aggregate at aggregate soffit will be the weak zone of geopolymer concrete.

关 键 词：地聚物 界面过渡区 偏高岭土 矿渣 花岗岩骨料 

分 类 号：TB332[一般工业技术—材料科学与工程]