Walkley, B, San Nicolas, R, Sani, M-A et al. (3 more authors) (2017) Structural evolution of synthetic alkali-activated CaO-MgO-Na₂O-Al₂O₃-SiO₂ materials is influenced by Mg content. Cement and Concrete Research, 99. pp. 155-171. ISSN 0008-8846
Abstract
Stoichiometrically controlled alkali-activated materials within the system CaO-MgO-Na₂O-Al₂O₃-SiO₂ are produced by alkali-activation of high-purity synthetic powders chemically comparable to the glass in ground granulated blast furnace slag, but without additional minor constituents. Mg content controls the formation of hydrotalcite-group and AFm-type phases, which in turn strongly affects C-(N)-A-S-H gel chemistry and nanostructure. Bulk Mg content and the Mg/Al ratio of hydrotalcite-group phases are strongly correlated. With sufficient Ca, increased bulk Mg promotes formation of low-Al C-(A)-S-H and portlandite, due to formation of hydrotalcite-group phases and a reduction in available Al. Hydrotalcite-group phase formation is linked to increased C-(N)-A-S-H gel polymerisation, decreased gel Al uptake and increased formation of the ‘third aluminate hydrate’. These findings highlight the importance of considering available chemical constituents rather than simply bulk composition, so that the desired binder structure for a particular application can be achieved.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier Ltd. This is an author produced version of a paper published in Cement and Concrete Research. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Alkali-activated cement (D); Aluminosilicate powder synthesis; Calcium-silicate-hydrate (C-S-H) (B); Layered double hydroxides; Spectroscopy (B) |
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: | 11 Sep 2018 13:53 |
Last Modified: | 11 Sep 2018 13:53 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.cemconres.2017.05.006 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:135515 |