Fresh and hardened properties of alkali-activated fly ash/slag binders: effect of fly ash source, surface area, and additives

Wang, Yanru and Cao, Yubin and Ma, Yuwei and Xiao, Shanshan and Hu, Jie and Wang, Hao (2021) Fresh and hardened properties of alkali-activated fly ash/slag binders: effect of fly ash source, surface area, and additives. Journal of Sustainable Cement-Based Materials. pp. 1-24. ISSN 2165-0373


Abstract

The variation of the raw materials is critical for the wide application of alkali-activated fly ash/slag (AAFS) in practice. In this study, four fly ashes sourced from different power plants were collected and analyzed. The calcium content in fly ash had insignificant impact on setting time, flowability and compressive strength of AAFS binders when the slag content was 50%. Low calcium content in fly ash promotes the formation of C-(N)A-S-H gel with high Al substitution and improves the compressive strength at later age. It seemed that the grinding process promoted the dissolution of reactive SiO2 in fly ash, resulting in reduced setting and flowability. The replacement of silica fume promotes the formation of Si-rich C-(N)A-S-H gel with reduced gel pore size. The replacement of metakaolin accelerated the initial reaction and increased the compressive strength of binders at early age due to the reduced gel pore size in C-(N)A-S-H gel.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 17 Jan 2022 23:03
Last Modified: 19 Jan 2022 02:36
Uncontrolled Keywords: Alkali activated; fly ash/slag binders; grinding; metakaolin; silica fume; source
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400505 Construction materials
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9699 Other Environment > 969999 Environment not elsewhere classified
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1899 Other environmental management > 189999 Other environmental management not elsewhere classified
Identification Number or DOI: https://doi.org/10.1080/21650373.2021.1932637
URI: http://eprints.usq.edu.au/id/eprint/45497

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