Early hydration kinetics and microstructure development of hybrid alkali activated cements (HAACs) at room temperature

Xue, Lili and Zhang, Zuhua and Wang, Hao (2021) Early hydration kinetics and microstructure development of hybrid alkali activated cements (HAACs) at room temperature. Cement and Concrete Composites, 123:104200. pp. 1-11. ISSN 0958-9465


Abstract

Hybrid alkali activated cement (HAAC) is considered as a promising alternative material to Portland cement due
to its low carbon emissions and excellent mechanical properties. In this study, HAACs were prepared using 75 %
granulated blast furnace slag (GBFS) and/or fly ash (FA) and 25 % Portland cement with external addition of
3%–5% alkali activator. The influence of precursors and Na2O content on hydration heat, reaction extent and
microstructural development were investigated to understand the early hydration kinetics. Through the char-
acterization via XRD quantitative analysis and 29Si NMR spectroscopy, it is shown that increasing the Na2O
content improved the compressive strength and reaction extent gradually despite the hydration process being
delayed in the first few hours. The much lower reactivity of FA led to slower hydration rate and lower reaction
extent of the HAACs containing more FA, thus reduced compressive strength yet only slightly delayed setting.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
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: 08 Mar 2022 01:28
Last Modified: 30 Mar 2022 05:16
Uncontrolled Keywords: hybrid alkali activated cement; early hydration; microstructural evolution; XRD quantitative analysis; deconvolution of NMR spectra
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401602 Composite and hybrid materials
40 ENGINEERING > 4005 Civil engineering > 400505 Construction materials
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280110 Expanding knowledge in engineering
Identification Number or DOI: https://doi.org/10.1016/j.cemconcomp.2021.104200
URI: http://eprints.usq.edu.au/id/eprint/46443

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