Zhu, X, Li, Q, Kang, X et al. (2 more authors) (2021) Nano-Structural Change of C(N)-A-S-H Gel in Alkali-Activated Slag Pastes Subjected to Wetting-Drying Cyclic Sulphate Attack. Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society, 49 (11). pp. 2529-2537. ISSN 2095-7645
Abstract
Nano-structural change of calcium(sodium) aluminium silicate hydrates ( C(N)-A-S-H) gel in alkali-activated slag (AAS) mortars after wetting-drying cyclic attack in 5 % (mass fraction,the same below) and 10% sulphate solutions was investigated. The structural and compositional changes of aluminosilicate chains in the main binding phases (C(N)-A-S-H) in AAS mortars were analyzed by Fourier-transform infrared spectroscopy, thermogravimetry-differential scanning calorimetry, 29Si magic angle spinning nuclear magnetic resonance, backscattered scanning electron microscopy and transmission electron microscopy-energy dispersive X-ray spectroscopy. The results show that the sulphate attack increases the degree of reaction of ground granulated blast-furnace slag regardless of sulphate salt type. The main corrosion products in MgSO4 solutions are gypsum, which is not detected in the samples subjected to Na2SO4 solutions. The C(N)-A-S-H with longer chains prefers to be attacked in MgSO4 solutions, whilst the end-members of the chains or short chains of C(N)-A-S-H are broken in Na2SO4 solutions. The C(N)-A-S-H after cyclic water attack is a mixture of tobermorite/jennite dimer to undecamer (T/J2-T/J11), while the Na2SO4 solutions attack results in the destroy of shorter chains and the increase of protonation (or Na-balanced ratio), thus forming a new C(N)-A-S-H gel.
Metadata
Item Type: | Article |
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Authors/Creators: |
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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: | 08 Dec 2021 14:52 |
Last Modified: | 08 Dec 2021 14:52 |
Status: | Published |
Publisher: | Chinese Ceramic Society |
Identification Number: | 10.14062/j.issn.0454-5648.20210038 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:181230 |