Zhu, X, Tang, D, Yang, K orcid.org/0000-0002-4223-2710 et al. (4 more authors) (2018) Effect of Ca(OH)₂ on shrinkage characteristics and microstructures of alkali-activated slag concrete. Construction and Building Materials, 175. pp. 467-482. ISSN 0950-0618
Abstract
The study presents the shrinkage behaviour of Ca(OH)2-added alkali-activated slag (AAS) concrete. A series of tests were performed to determine the plastic shrinkage, autogenous shrinkage and drying shrinkage. In order to explain shrinkage mechanisms, the moisture loss was monitored; the pore structure was examined by nitrogen adsorption test; hydration process was assessed by isothermal calorimetry; hydration products and microstructure were characterised by XRD, SEM/EDS and TG/DTG. It was found that the use of Ca(OH)2 increased the plastic shrinkage of AAS concrete, but reduced autogenous and drying shrinkage. This is because the addition of Ca(OH)2 accelerated the hydration at very early stage, while non-noticeable impact could be identified after 120 h. The results from nitrogen adsorption test showed a decrease in mesopores by adding Ca(OH)2, which was responsible for the less drying and autogenous shrinkage. Meanwhile, the Ca/Si of C-S-H (I) increased from 0.89 to around 1.40 at 28 d when adding 5% and 10% Ca(OH)2. XRD patterns indicated C2ASH8 and C4AH13 were found in Ca(OH)2-added samples. These changes in hydration products also contribute less drying and autogenous shrinkage in Ca(OH)2-added samples.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | Crown Copyright © 2018 Published by Elsevier Ltd. This is an author produced version of a paper published in Construction and Building Materials. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Alkali-activated slag concrete; Calcium hydroxide; Shrinkage; Pore structure; Hydration process; Hydration products |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Aug 2018 10:20 |
Last Modified: | 30 Jun 2019 00:43 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.conbuildmat.2018.04.180 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134814 |