Bacteria-induced internal carbonation of reactive magnesia cement

被引：38

作者：

Xiao, Xi ^{[1
]}

Goh, Li Xuan ^{[1
]}

Unluer, Cise ^{[2
]}

Yang, En-Hua ^{[1
]}

机构：

[1] Nanyang Technol Univ, Sch Civil & Environm Engn, 50 Nanyang Ave, Singapore 639798, Singapore

[2] Univ Glasgow, Sch Engn, Glasgow G12 8LT, Lanark, Scotland

来源：

CONSTRUCTION AND BUILDING MATERIALS | 2021年 / 267卷

关键词：

MgO; Bacteria; Urea; Internal carbonation; Performance; ENHANCED HYDRATION; NITROUS-OXIDE; UREA; MGO; CONCRETE; SEQUESTRATION; OXIDATION; AMMONIA; CO2;

D O I：

10.1016/j.conbuildmat.2020.121748

中图分类号：

TU [建筑科学];

学科分类号：

0813 ;

摘要：

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 bioRMC pastes, which is responsible for the strength gain of the bio-RMC pastes. (C) 2020 Elsevier Ltd. All rights reserved.

引用

页数：8