Metakaolin-based geopolymers: Relation between formulation, physicochemical properties and efflorescence formation

Longhi, Marlon A. and Rodriguez, Erich D. and Walkley, Brant and Zhang, Zuhua and Kirchheim, Ana Paula (2020) Metakaolin-based geopolymers: Relation between formulation, physicochemical properties and efflorescence formation. Composites Part B: Engineering, 182 (Article 107671). pp. 1-15. ISSN 1359-8368


Abstract

The efflorescence formation in metakaolin-based geopolymers is assessed in this study to provide a better understanding of the effect of the synthesis parameters. Efflorescence formation depends on the physical and chemical properties of geopolymers as well as the environmental exposure conditions. In this study a set of fifteen geopolymers were synthesized using different formulation. An accelerated test of efflorescence development is presented, where the grade of degradation was evaluated by visual observation and correlated to leaching potential, physical properties and microstructural features. The use of soluble silicate in the activator provides a denser and a less permeable matrix. This makes the extraction of free alkalis to the surface more difficult, reducing the extent of alkali leaching and therefore efflorescence. The use of K+ is also effective to reduce visible efflorescence. The efflorescence formation is predicted by the properties of the gel formed which are dependent on the mix proportioning.


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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 04:17
Last Modified: 08 May 2020 01:48
Uncontrolled Keywords: Alkali-activated cement (AAC); Geopolymer; Metakaolin; Efflorescence; Leaching
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
Identification Number or DOI: https://doi.org/10.1016/j.compositesb.2019.107671
URI: http://eprints.usq.edu.au/id/eprint/37678

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