On the hydration of Belite-Ye'elimite-Ferrite (BYF) cement pastes: Effect of the water-to-cement ratio and presence of fly ash

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Author(s):	Koga, Guilherme Yuuki ; Albert, Blandine ; Nogueira, Ricardo Pereira Total Authors: 3
Document type:	Journal article
Source:	CEMENT AND CONCRETE RESEARCH; v. 137, p. 12-pg., 2020-11-01.
Abstract
This work reports the evolution of the phase assemblage, pore solution, porosity, and mechanical resistance of Belite-Ye'elimite-Ferrite (BYF) cement pastes. Different water-to-cement (w/c) ratios were considered and the addition of fly ash (FA) evaluated. The initial 1-day hydration of BYF cement paste was characterized by the ye'elimite hydration accompanied by a pronounced alkalinity increase controlled mainly by the molar ratio of calcium sulfate to ye'elimite. Throughout the 1-year test, the phase assemblages of 0.50 and 0.67 w/c samples were similar, composed of ettringite, AFm, stratlingite, silicious hydrogarnet, and C-S-H. The hydration of the 0.40 w/c cement paste was almost complete within a month. Additions of 25 wt% FA increased the fraction of stratlingite and ettringite without long-term strength losses compared to plain BYF cement paste with the same water-to-binder ratio. Results from different characterization techniques for both liquid and solid phases at early-age (first 24 h) were complemented by thermodynamic calculations. (AU)

FAPESP's process:	19/02136-3 - Corrosion of Spray-Formed high entropy alloys
Grantee:	Alberto Moreira Jorge Junior
Support Opportunities:	Research Grants - Visiting Researcher Grant - International