Jia, S and Richardson, IG (2018) Micro- and nano-structural evolutions in white Portland cement/pulverized fuel ash cement pastes due to deionized-water leaching. Cement and Concrete Research, 103. pp. 191-203. ISSN 0008-8846
Abstract
Thin slices of white Portland cement-low calcium pulverized fuel ash (pfa) blended cement pastes containing 30 or 50% pfa were leached progressively in de-ionized water. The paste with 50% pfa was aged 13 years prior to leaching and those with 30% pfa were aged 1 and 13 years. Pastes were leached for up to 75 days and were characterized using thermal analysis, X-ray diffraction, analytical scanning and transmission electron microscopy, and solid-state nuclear magnetic resonance spectroscopy. Leaching affected the pastes in the following sequence: (i) crystals of Ca(OH)2 large enough to be resolved by backscattered electron imaging were removed completely prior to any effect on C-A-S-H; (ii) the Ca/Si ratio of C-A-S-H reduced from ≈1.4 to ≈1.0 whilst the aluminosilicate structure was unaffected; (iii) further reduction in the Ca/Si ratio of C-A-S-H was accompanied by lengthening of the aluminosilicate chains; (iv) the Ca/Si ratio of C-A-S-H reduced ultimately to ≈0.6.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY). |
Keywords: | Fly ash; Calcium silicate hydrate (C-A-S-H); TEM; Leaching; Radioactive waste |
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) |
Funding Information: | Funder Grant number Nuclear Decommissioning Authority NR 3374 |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Nov 2017 15:14 |
Last Modified: | 19 Aug 2019 14:47 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.cemconres.2017.10.014 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123476 |