Ke, X., Bernal, S.A. and Provis, J.L. orcid.org/0000-0003-3372-8922 (2017) Uptake of chloride and carbonate by Mg-Al and Ca-Al layered double hydroxides in simulated pore solutions of alkali-activated slag cement. Cement and Concrete Research, 100. pp. 1-13. ISSN 0008-8846
Abstract
Chloride ingress and carbonation are major causes of degradation of reinforced concrete. To enable prediction of chloride ingress, and thus to improve the durability of structural alkali-activated slag cement (AAS) based concretes, it is necessary to understand the ionic interactions taking place between chlorides, carbonates, and the individual solid phases which comprise AAS. This study focused on two layered double hydroxides (LDH) representing those typically identified as reaction products in AAS: an Mg-Al hydrotalcite-like phase, and an AFm structure (strätlingite), in simulated AAS pore solutions. Surface adsorption and interlayer ion-exchange of chlorides occurred in both LDH phases; however, chloride uptake in hydrotalcite-group structures is governed by surface adsorption, while strätlingite shows the formation of a hydrocalumite-like phase and ion exchange. For both Ca-Al and Mg-Al LDHs, decreased chloride uptakes were observed from solutions with increased [CO32−]/[OH−] ratios, due to the formation of carbonate-containing hydrotalcite and decomposition of AFm phases, respectively.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). |
Keywords: | Adsorption (C); Alkali-activated cement (D); Chloride (D); Durability (D); Pore solution (B) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Funding Information: | Funder Grant number EUROPEAN RESEARCH COUNCIL GeopolyConc - 335928 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 13 Jun 2017 09:25 |
Last Modified: | 13 Jun 2017 09:25 |
Published Version: | http://doi.org/10.1016/j.cemconres.2017.05.015 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.cemconres.2017.05.015 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:117603 |