Quantitative Characterization and Elastic Properties of Interfacial Transition Zone around Coarse Aggregate in Concrete  

作　　者：贾子健 HAN Yunge 张亚梅 QIU Chen HU Chuanlin LI Zongjin 

机构地区：[1]School of Materials Science and Engineering, Jiangsu Key Laboratory of Construction Materials, Southeast University, Nanjing 211189, China [2]Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2017年第4期838-844,共7页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(No.51178105);the Major State Basic Research Development Program of China(973 Program)(No.2015CB655104);the Collaborative Innovation Centre for Advanced Civil Engineering Materials

摘　　要：Backscattered electron images（BSE） obtained by scanning electron microscope was used to quantitatively characterize the microstructure of interfacial transition zone（ITZ） in concrete. Influences of aggregate size（5, 10, 20, and 30 mm）, water to cement ratio（0.23, 0.35 and 0.53） and curing time（from 3d to 90d） on the microstructure of interfacial transition zone between coarse aggregate and bulk cement matrix were investigated. The volume percentage of detectable porosity and unhydrated cement in ITZ was quantitatively analyzed and compared with that in the matrix of various concretes. Nanoindentation technology was applied to obtain the elastic properties of ITZ and matrix, and the elastic modulus of concrete was then calculated based on the Lu ＆ Torquato model and self-consistence scheme by using the ITZ thickness and elastic modulus obtained from this investigation. The experimental results demonstrated that the microstructure and thickness of ITZ in concrete vary with a variety of factors, like aggregate size, water to cement ratio and curing time. The relative low elastic properties of ITZ should be paid attention to, especially for early age concrete.Backscattered electron images（BSE） obtained by scanning electron microscope was used to quantitatively characterize the microstructure of interfacial transition zone（ITZ） in concrete. Influences of aggregate size（5, 10, 20, and 30 mm）, water to cement ratio（0.23, 0.35 and 0.53） and curing time（from 3d to 90d） on the microstructure of interfacial transition zone between coarse aggregate and bulk cement matrix were investigated. The volume percentage of detectable porosity and unhydrated cement in ITZ was quantitatively analyzed and compared with that in the matrix of various concretes. Nanoindentation technology was applied to obtain the elastic properties of ITZ and matrix, and the elastic modulus of concrete was then calculated based on the Lu ＆ Torquato model and self-consistence scheme by using the ITZ thickness and elastic modulus obtained from this investigation. The experimental results demonstrated that the microstructure and thickness of ITZ in concrete vary with a variety of factors, like aggregate size, water to cement ratio and curing time. The relative low elastic properties of ITZ should be paid attention to, especially for early age concrete.

关 键 词：concrete interfacial transition zone backscattered electron image nanoindentation elastic modulus 

分 类 号：TU528[建筑科学—建筑技术科学] TU528.01