Compressive strength development and shrinkage of alkali-activated fly ash–slag blends associated with efflorescence

Yao, Xiao and Yang, Tao and Zhang, Zuhua (2016) Compressive strength development and shrinkage of alkali-activated fly ash–slag blends associated with efflorescence. Materials and Structures, 49 (7). pp. 2907-2918. ISSN 1359-5997

Abstract

This study reports the changes in the compressive strength and shrinkage property of alkali-activated fly ash and slag (AAFS) blends associated with efflorescence. The AAFS specimens cured in air for different periods were further aged under the following three conditions: bottom-contact with water, fully immersed in water and in air. The second condition, i.e., bottom in contact with water, was used to accelerate efflorescence of AAFS. The efflorescence of the AAFS binders was dependent on the reaction extent of the solid precursors. A higher reaction extent present in the binder by extending initial-curing age can reduce efflorescence rate. The incorporation of low percentage of slag (lower than 50 wt%) in the AAFS binders has little influence on the efflorescence potential, while with the increased contents of slag higher than 50 %, the binders exhibit more rapid efflorescence than the 100 % fly ash binders. The efflorescence led to the strength loss because of the formation of carbonate crystals in the binder and the damage of the microstructure. The linear shrinkage of the binders was also related to efflorescence and alkali leaching. The slag addition can reduce the negative effects of efflorescence and alkali leaching on the absolute compressive strength and shrinkage of the binders.


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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 / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering
Date Deposited: 03 Apr 2017 05:38
Last Modified: 03 Apr 2017 06:04
Uncontrolled Keywords: alkali activated cement; efflorescence; fly ash; pore structure; slag
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091299 Materials Engineering not elsewhere classified
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: 10.1617/s11527-015-0694-3
URI: http://eprints.usq.edu.au/id/eprint/31063

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