Abstract
The current understanding of the carbonation of alkali-activated concretes is hampered inter alia by the wide range of binder chemistries used. To overcome some of the limitations of individual studies and to identify general correlations between their mix design parameters and carbonation resistance, the RILEM TC 281-CCC working group 6 compiled carbonation data for alkali-activated concretes and mortars from the literature. For comparison purposes, data for blended Portland cement-based concretes with a high percentage of SCMs (≥ 66% of the binder) were also included in the database. A preliminary analysis of the database indicates that w/CaO ratio and w/b ratio exert an influence on the carbonation resistance of alkali-activated concretes but, contrary to what has been reported for concretes based on (blended) Portland cements, these are not good indicators of their carbonation resistance when considered individually. A better indicator of the carbonation resistance of alkali-activated concretes under conditions approximating natural carbonation appears to be their w/(CaO + Na2O + K2O) ratio. Furthermore, the analysis points to significant shortcomings of tests at elevated CO2 concentrations for low-Ca alkali-activated concretes, indicating that even at a concentration of 1% CO2, the outcomes may lead to inaccurate predictions of the carbonation coefficient under natural exposure conditions.
Original language | English |
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Title of host publication | Proceedings of the 75th RILEM Annual Week 2021 |
Subtitle of host publication | Advances in Sustainable Construction Materials and Structures |
Publisher | Springer |
Pages | 667-676 |
Number of pages | 10 |
Volume | 40 |
ISBN (Electronic) | 978-3-031-21735-7 |
ISBN (Print) | 978-3-031-21734-0 |
DOIs | |
Publication status | Published - 2023 |
Publication series
Name | RILEM Bookseries |
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Volume | 40 |
ISSN (Print) | 2211-0844 |
ISSN (Electronic) | 2211-0852 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- Accelerated testing
- Alkali-activated materials
- Carbonation
- Natural exposure