Fly ash-based geopolymers: the relationship between composition, pore structure and efflorescence
Article
Article Title | Fly ash-based geopolymers: the relationship between composition, pore structure and efflorescence |
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ERA Journal ID | 4164 |
Article Category | Article |
Authors | Zhang, Zuhua (Author), Provis, John L. (Author), Reid, Andrew (Author) and Wang, Hao (Author) |
Journal Title | Cement and Concrete Research |
Journal Citation | 64, pp. 30-41 |
Number of Pages | 12 |
Year | 2014 |
Publisher | Elsevier |
Place of Publication | Kidlington, OX. United Kingdom |
ISSN | 0008-8846 |
1873-3948 | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.cemconres.2014.06.004 |
Abstract | This study reports the observation of efflorescence in fly ash-based geopolymers. The efflorescence rate strongly depends on the activation conditions; at the same alkali content under ambient temperature curing, NaOH-activated geopolymers show less and slower efflorescence than sodium silicate-activated specimens. Geopolymers synthesised at high temperature exhibit much lower efflorescence than those synthesised at low temperature, except for the sodium silicate-activated samples. The substitution of 20% fly ash by slag reduces the efflorescence rate. A relationship between alkali leaching from monosized fractured particles and 'efflorescence potential' is proposed. Soluble silicate and slag addition are beneficial in reducing efflorescence rate, but have very limited influence on the overall efflorescence potential, as they appear to have a delaying rather than mitigating effect. The partial crystallisation of geopolymers, by curing at high temperature, appears to be the most effective method of reducing the efflorescence potential. |
Keywords | alkali activated cement; carbonation; durability; fly ash; pore size distribution |
ANZSRC Field of Research 2020 | 340306. Polymerisation mechanisms |
401205. Experimental methods in fluid flow, heat and mass transfer | |
340204. Inorganic green chemistry | |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Centre of Excellence in Engineered Fibre Composites |
University of Sheffield, United Kingdom | |
Halok Engineering, Australia | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q2887/fly-ash-based-geopolymers-the-relationship-between-composition-pore-structure-and-efflorescence
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