Mechanical property and structure of alkali-activated fly ash and slag blends

Yang, Tao and Yao, Xiao and Zhang, Zuhua and Wang, Hao (2012) Mechanical property and structure of alkali-activated fly ash and slag blends. Journal of Sustainable Cement-Based Materials, 1 (4). pp. 167-178. ISSN 2165-0373

Abstract

Mechanical property and structure of alkali-activated fly ash (FA)/ground granulated blast furnace slag (GGBFS) blends were investigated via compressive strength testing, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR),and scanning electron microscopy/energy dispersive spectroscopy. It is shown that
the incorporation of slag into solid precursors can improve compressive strength of the geopolymer binders and the optimal slag content ratio which will result in the
highest strength is 0.8. GGBFS is relatively more reactive than FA in alkaline activation. The binder is predominantly a class of Al-substituted sodium calcium silicate hydrate (N-C-A-S-H) gel phase, which distributes around the solid particles homogeneously. Combining the results obtained from the glass diffraction maximum of XRD and the wavenumber of T-O-Si bands displayed in FTIR, it suggests that the degree of polymerization of geopolymer binders decreases and increases. This means that the microstructure of the binder is more complex. The microstructure and chemical composition of the binders are between those of aluminosilicate gel formed in silicate-activated FA and those of calcium silicate hydrate gel formed in silicate-activated GGBFS. The major reasons contributing to this structure are the numerous calcium cations which will lead to a depolymerisation in fl uence on the network, and/or the majority of linear chains of Si-O-Si supplied by GGBFS.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Copyright 2012 Taylor & Francis. Permanent restricted access to published version in accordance with the copyright policy of the publisher.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Mechanical and Mechatronic Engineering
Date Deposited: 20 May 2013 07:02
Last Modified: 13 Dec 2017 00:42
Uncontrolled Keywords: geopolymer; fly ash; slag; alkali activation; aluminosilicates
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
09 Engineering > 0912 Materials Engineering > 091209 Polymers and Plastics
09 Engineering > 0913 Mechanical Engineering > 091307 Numerical Modelling and Mechanical Characterisation
Socio-Economic Objective: B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870399 Construction Materials Performance and Processes not elsewhere classified
B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870303 Polymeric Materials (e.g. Paints)
Identification Number or DOI: 10.1080/21650373.2012.752621
URI: http://eprints.usq.edu.au/id/eprint/22530

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