Efflorescence and subflorescence induced microstructural and mechanical evolution in fly ash-based geopolymers
Article
Article Title | Efflorescence and subflorescence induced microstructural and mechanical evolution in fly ash-based geopolymers |
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ERA Journal ID | 21082 |
Article Category | Article |
Authors | Zhang, Zuhua (Author), Provis, John L. (Author), Reid, Andrew (Author) and Wang, Hao (Author) |
Journal Title | Cement and Concrete Composites |
Journal Citation | 92, pp. 165-177 |
Number of Pages | 13 |
Year | 2018 |
Publisher | Elsevier |
Place of Publication | United Kingdom |
ISSN | 0958-9465 |
1873-393X | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.cemconcomp.2018.06.010 |
Web Address (URL) | https://www.sciencedirect.com/science/article/pii/S0958946518302622#ack0010 |
Abstract | This paper reports the effects of efflorescence on the microstructural and mechanical properties of fly ash-based geopolymers. Geopolymer pastes manufactured by sodium hydroxide and sodium silicate activation of three Class F fly ashes exhibit varying efflorescence behaviour. The geopolymer derived from sodium silicate activation of fine fly ash, which has a compact microstructure, shows a relatively slow efflorescence rate and low efflorescence potential. The efflorescence occurring on the surface of the geopolymer specimens does not change their mineralogical characteristics. However, the compressive strength development and compressive modulus of geopolymers can be affected through processes related to the loss of alkalis, and also to subflorescence. The phenomenon of subflorescence can be regarded as an extended efflorescence taking place under the surface of the material, leading to crystallisation pressure, which may exceed the tensile strength of hardened binders and generate structural damage. |
Keywords | alkali activated cement; fly ash; durability; microstructure; mechanical properties |
ANZSRC Field of Research 2020 | 401602. Composite and hybrid materials |
Public Notes | File reproduced in accordance with the copyright policy of the publisher/author. |
Byline Affiliations | Centre for Future Materials |
University of Sheffield, United Kingdom | |
Halok Engineering, Australia | |
Institution of Origin | University of Southern Queensland |
Funding source | Australian Research Council (ARC) Grant ID DP160104149; DE170101070). |
https://research.usq.edu.au/item/q4zq7/efflorescence-and-subflorescence-induced-microstructural-and-mechanical-evolution-in-fly-ash-based-geopolymers
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