Hydrothermal transformation of the calcium aluminum oxide hydrates CaAl{sub 2}O{sub 4}.10H{sub 2}O and Ca{sub 2}Al{sub 2}O{sub 5}.8H{sub 2}O to Ca{sub 3}Al{sub 2}(OH){sub 12} investigated by in situ synchrotron X-ray powder diffraction

Journal Article · Wed Dec 14 23:00:00 EST 2005 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2004.1· OSTI ID:20793260

Jensen, Torben R ^[1]; Christensen, Axel Norlund ^[2]; Hanson, Jonathan C ^[3]

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1. Interdisciplinary Nanoscience Center, Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus C (Denmark)
2. Hojkolvej 7, DK-8210 Arhus V (Denmark)
3. Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, USA (United States)

The hydrothermal transformation of calcium aluminate hydrates were investigated by in situ synchrotron X-ray powder diffraction in the temperature range 25 to 170 deg. C. This technique allowed the study of the detailed reaction mechanism and identification of intermediate phases. The material CaAl{sub 2}O{sub 4}.10H{sub 2}O converted to Ca{sub 3}Al{sub 2}(OH){sub 12} and amorphous aluminum hydroxide. Ca{sub 2}Al{sub 2}O{sub 5}.8H{sub 2}O transformed via the intermediate phase Ca{sub 4}Al{sub 2}O{sub 7}.13H{sub 2}O to Ca{sub 3}Al{sub 2}(OH){sub 12} and gibbsite, Al(OH){sub 3}. The phase Ca{sub 4}Al{sub 2}O{sub 7}.19H{sub 2}O reacted via the same intermediate phase to Ca{sub 3}Al{sub 2}(OH){sub 12} and mainly amorphous aluminum hydroxide. The powder pattern of the intermediate phase is reported.

• OSTI ID: 20793260
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 12 Vol. 35; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ALUMINIUM HYDROXIDES
ALUMINIUM OXIDES
CALCIUM COMPOUNDS
CEMENTS
GIBBSITE
HYDRATES
HYDRATION
REACTION KINETICS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION