Correlation of chloride diffusion coefficient and microstructure parameters in concrete: A comparative analysis using NMR,MIP, and X-CT  

作　　者：Yurong ZHANG Shengxuan XU Yanhong GAO Jie GUO Yinghui CAO Junzhi ZHANG 

机构地区：[1]College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310014,China [2]Key Laboratory of Civil Engineering Structure&Disaster Prevention and Mitigation Technology of Zhejiang Province,Hangzhou 310014,China

出　　处：《Frontiers of Structural and Civil Engineering》2020年第6期1509-1519,共11页结构与土木工程前沿（英文版）

基　　金：Thanks to the financial supports provided by the Natural Science Foundation of Zhejiang Province(LY17E090007,LQ18G010007,and LY19E90006);the National Natural Science Foundation of China(Grant No.51279181).

摘　　要：Permeability is a major indicator of concrete durability,and depends primarily on the microstructure characteristics of concrete,including its porosity and pore size distribution.In this study,a variety of concrete samples were prepared to investigate their microstructure characteristics via nuclear magnetic resonance(NMR),mercury intrusion porosimetry(MIP),and X-ray computed tomography(X-CT).Furthermore,the chloride diffusion coefficient of concrete was measured to explore its correlation with the microstructure of the concrete samples.Results show that the proportion of pores with diameters<1000 nm obtained by NMR exceeds that obtained by MIP,although the difference in the total porosity determined by both methods is minimal.X-CT measurements obtained a relatively small porosity;however,this likely reflcts the distribution of large pores more accurately.A strong correlation is observed between the chloride diffusion coefficient and the porosity or contributive porosity of pores with sizes<1000 nm.Moreover,microstructure parameters measured via NMR reveal a lower correlation coefficient R2 versus the chloride diffusion coefficient relative to the parameters determined via MIP,as NMR can measure non-connected as well as connected pores.In addition,when analyzing pores with sizes>50 um,X-CT obtains the maximal contributive porosity,followed by MIP and NMR.

关 键 词：PERMEABILITY microstructure NMR MIP X-CT 

分 类 号：TU528[建筑科学—建筑技术科学]