TY - JOUR
T1 - Properties of interfacial transition zones in recycled aggregate concrete tested by nanoindentation
AU - Xiao, Jianzhuang
AU - Li, Wengui
AU - Sun, Zhihui
AU - Lange, David A.
AU - Shah, Surendra P.
N1 - Funding Information:
The authors would like to gratefully acknowledge the financial support from the National Natural Science Foundation of China (51178340), and the Kwang-Hua Foundation. The authors gratefully thank Dr. Gajendra Shekhawat and Dr. David J. Corr in Northwestern University for their supports. The second author would also like to thank China Scholarship Council (CSC) for its partial financial support during his study at Northwestern University, USA.
PY - 2013/3
Y1 - 2013/3
N2 - The properties of new Interfacial Transition Zone (ITZ) and old ITZ in Recycled Aggregate Concrete (RAC) were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and nanoindentation. From the SEM images, obvious voids and high concentration of calcium hydroxide can be found in both old ITZ and new ITZ in RAC. Based on the nanoindentation study, it is indicated that the thicknesses of old and new ITZs are in the range 40-50 μm and in the range 55-65 μm, respectively. It is also found that the average indentation modulus of old ITZ is 70-80% of that of old paste matrix, while the average indentation modulus of new ITZ is 80-90% of that of new paste matrix. Additionally, the influences of mix proportion, aggregate types and hydration age on the properties of ITZs in RAC are discussed in this study.
AB - The properties of new Interfacial Transition Zone (ITZ) and old ITZ in Recycled Aggregate Concrete (RAC) were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and nanoindentation. From the SEM images, obvious voids and high concentration of calcium hydroxide can be found in both old ITZ and new ITZ in RAC. Based on the nanoindentation study, it is indicated that the thicknesses of old and new ITZs are in the range 40-50 μm and in the range 55-65 μm, respectively. It is also found that the average indentation modulus of old ITZ is 70-80% of that of old paste matrix, while the average indentation modulus of new ITZ is 80-90% of that of new paste matrix. Additionally, the influences of mix proportion, aggregate types and hydration age on the properties of ITZs in RAC are discussed in this study.
KW - Atomic Force Microscope (AFM)
KW - Interfacial Transition Zone (ITZ)
KW - Microstructure
KW - Nanoindentation
KW - Nanomechanical properties
KW - Recycled Aggregate Concrete (RAC)
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U2 - 10.1016/j.cemconcomp.2013.01.006
DO - 10.1016/j.cemconcomp.2013.01.006
M3 - Article
AN - SCOPUS:84874648028
SN - 0958-9465
VL - 37
SP - 276
EP - 292
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
IS - 1
ER -