Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7885638 | Cement and Concrete Research | 2014 | 8 Pages |
Abstract
Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (α). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (α ~ 70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with β- and αâ²H-belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (α ~ 25% at 1 h) than in the active-BCSA one (α ~ 10% at 1 h), with differences in the crystallization of ettringite (α ~ 30% and α ~ 5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail.
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Authors
G. Álvarez-Pinazo, A. Cuesta, M. GarcÃa-Maté, I. Santacruz, E.R. Losilla, S.G. Sanfélix, F. Fauth, M.A.G. Aranda, A.G. De la Torre,