Aluminum hydroxide gel characterization within a calcium aluminate cement paste by combined Pair Distribution Function and Rietveld analyses. (June 2017)

• Record Type: Journal Article
• Authors: Cuesta, Ana; Ichikawa, Rodrigo U.; Londono-Zuluaga, Diana; De la Torre, Angeles G.; Santacruz, Isabel; Turrillas, Xavier; Aranda, Miguel A.G.
• Is Part Of: Cement and concrete research. Volume 96(2017)
• Page Start: 1
• Page End: 12
• Publication Date: 2017-06
• Subjects: X-ray diffraction (B) -- Calcium aluminate cement (D) -- Hydrogarnet (D) -- Amorphous material (A) -- Aluminum hydroxide gel (D); Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2017.02.025
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: There are many commercially important multiphase materials which contain amorphous phases, such as cement pastes, porcelains, glass-ceramics or pharmaceutical compounds. However, the analysis of amorphous phase(s) within cement matrices that contain high amounts of crystalline phase(s) is a challenge. Here, we report measurements of total scattering data quantitatively analyzed by Pair Distribution Function (PDF) minimization and Rietveld methodology to determine phase compositions including both amorphous and nanocrystalline phase contents in cement-related samples. Furthermore, laboratory techniques were used to complement the sample characterization. In addition to five reference materials, the main phase of calcium aluminate cements, CaAl2 O4 hydrated at 50 °C to yield crystalline hydrogarnet, Ca3 Al2 (OH)12, (43 wt%) and nanocrystalline aluminum hydroxide gel, Al(OH)3 ·0.1H2 O (50 wt%) was also investigated. The PDF analyses revealed that the hydroxide gel has a gibbsite local structure with an average particle size close to 5 nm. PDF and Rietveld quantitative phase analysis results fully agree.