Geopolymer with improved thermal stability by incorporating high-magnesium nickel slag

Yang, Tao and Wu, Qisheng and Zhu, Huajun and Zhang, Zuhua (2017) Geopolymer with improved thermal stability by incorporating high-magnesium nickel slag. Construction and Building Materials, 155. pp. 475-484. ISSN 0950-0618


Abstract

The present study investigates the thermal stability of binary geopolymers prepared with fly ash and high magnesium nickel slag (HMNS). TGA, XRD and SEM techniques are adopted to investigate the chemical composition and microstructure of the binder gel phase exposed to high temperatures. The results show that incorporating HMNS mitigates dehydration induced mass loss and volume shrinkage of the geopolymer samples between room temperature and 250 °C, and increases their residual strengths when exposed to high temperatures between 600 °C and 800 °C. The key role that HMNS substitution of improving the thermal stability of geopolymers is associated with the formation of sodium alumina(magnesia)-silica hydrate (N-A(M)-S-H) gel phase, which turns to be a less porous microstructure after thermal exposure when compared with the N-A-S-H gel phase, which is formed in the pure fly ash sample. The binary geopolymers exhibit higher residual strengths and better maintaining of volume stability in the range from 250 °C to 550 °C compared to Portland cements. However, both the geopolymer and Portland cement show severer volume shrinkage after exposure of 600 °C, because of the viscous sintering of geopolymer gels and the decomposition of cement hydration products, respectively.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
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: 31 Jan 2020 05:58
Last Modified: 13 Feb 2020 22:51
Uncontrolled Keywords: Geopolymer; Nickel slag; Fly ash; Thermal stability
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
Socio-Economic Objective: B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870301 Cement and Concrete Materials
Funding Details:
Identification Number or DOI: 10.1016/j.conbuildmat.2017.08.081
URI: http://eprints.usq.edu.au/id/eprint/37704

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