Osio-Norgaard, J, Aday, AN, Chen, X et al. (3 more authors) (2021) Silica-modifying chemical admixtures for directed zeolitization of metakaolin-based alkali-activated materials. Cement and Concrete Research, 142. 106348. ISSN 0008-8846
Abstract
The effect of using trimethyladamantyl-ammonium hydroxide (TMAAOH) as a silica-modifying admixture to induce early-age mineralization during alkali-activation of metakaolin was investigated and reported herein. In all material formulations, the use of TMAAOH induced early-age mineralization, increased mixture stiffening in the fresh state, and lowered total heat of reaction. In activating solutions with silica moduli above unity (Ms >1.0), mineralogy results demonstrate that TMAAOH induces the nucleation and growth of metastable zeolitic phases, which correlated with increased permeability and increased plastic shrinkage of the paste. When TMAAOH was added to activating solutions with silica moduli near unity (Ms ~1.0), the controlled formation of crystalline, silica-rich faujasite was observed, which correlated with reduced permeability and lower plastic shrinkage. Together, these results demonstrate for the first time that silica-templating agents such as TMAAOH can be exploited in the deisgn of new chemical admixtures that directly influence the dynamics of zeolitization in alkali-activated materials.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Cement and Concrete Research. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Zeolites; Mineralization; Alkali-activated cements; Rheology |
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 EU - European Union 839436 |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 May 2021 12:01 |
Last Modified: | 16 Jan 2022 01:38 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.cemconres.2020.106348 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:173946 |