Abstract
This study focuses on the development of carbonated reactive magnesia cement (RMC) concrete formulations involving hydromagnesite (H), magnesite (M) and hydration agent (HA). Partial replacement of RMC by H and M stimulated the formation of hydrate and carbonate phases. Use of H increased the rate and degree of hydration, resulting in the formation of a bird nest-like structure containing poorly-crystalline brucite. The higher propensity of this poorly-crystalline phase for carbonation increased the utilisation of RMC as a binder and facilitated its conversion into strength-providing HMCs. Synergistic combination of M and HA led to significant strength gain via increased carbonate content and reduced w/b ratio. Presence of M provided micro-aggregates that facilitated the enhanced formation of large carbonate crystals with improved morphologies, resulting in microstructure densification and 113 % strength increase. Furthermore, partial replacement of RMC with M enabled reduction of natural resources, CO2 emissions and energy consumption associated with RMC production.
Original language | English |
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Article number | 101834 |
Pages (from-to) | 1-17 |
Number of pages | 17 |
Journal | Journal of CO2 Utilization |
Volume | 56 |
Early online date | 3 Dec 2021 |
DOIs | |
Publication status | Published - Feb 2022 |
Keywords
- additives
- CO sequestration
- MgO
- microstructure
- performance