Bacteria-induced internal carbonation of reactive magnesia cement

Xi Xiao, Li Xuan Goh, C Unluer, EH Yang

Research output: Contribution to journalArticlepeer-review

Abstract

With lower calcination temperature, reactive magnesia cement (RMC) can be a potential alternative to the Portland cement. However, RMC concrete requires accelerated carbonation curing from external sources which greatly hinder the wider applications of RMC. This study proposed a bacteria-based method for the strength gain of RMC through internal carbonation. Sporosarcina pasteurii, urea, and yeast extract were used as a carbonation agent for internal carbonation of RMC pastes. Results showed that the flowability of the fresh bio-RMC paste increased by 20% while the initial setting time remained unchanged. Besides serving as the CO2 provider, urea can also function as superplasticizer to reduce the water demand of the bio-RMC pastes. The resulting bio-RMC pastes showed a continuous strength gain with time, demonstrating the feasibility of bacteria-induced internal carbonation of RMC. Microstructure analysis revealed abundant formation of hydrated magnesium carbonates in the bio-RMC pastes, which is responsible for the strength gain of the bio-RMC pastes.
Original languageEnglish
Article number121748
Pages (from-to)1-8
Number of pages8
JournalConstruction and Building Materials
Volume267
Early online date7 Dec 2020
DOIs
Publication statusPublished - 18 Jan 2021

Keywords

  • bacteria
  • internal carbonation
  • MgO
  • performance
  • Urea

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