Hydration of MgO/SiO2 and Portland cement mixtures: A structural investigation of the hydrated phases by means of X-ray diffraction and solid state NMR spectroscopy. (December 2017)

• Record Type: Journal Article
• Authors: Martini, Francesca; Tonelli, Monica; Geppi, Marco; Ridi, Francesca; Borsacchi, Silvia; Calucci, Lucia
• Is Part Of: Cement and concrete research. Volume 102(2017)
• Page Start: 60
• Page End: 67
• Publication Date: 2017-12
• Subjects: M-S-H magnesium silicate hydrate -- C-S-H calcium silicate hydrate -- w/s water to solid ratio -- M MgO -- S SiO2 -- C Portland cement -- SSNMR solid state Nuclear Magnetic Resonance -- DTA differential thermal analysis -- DE direct excitation -- MAS magic angle spinning -- FTIR Fourier transform infrared -- XRD X-ray diffraction -- RD reaction degree -- CD condensation degree -- MCLmin minimum mean chain length -- MCLmax maximum mean chain length -- MCL mean chain length; Magnesium silicate hydrate (M-S-H) -- Calcium silicate hydrate (C-S-H) (B) -- MgO (D) -- Portland cement (D) -- Solid state NMR -- X-ray diffraction (B); Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2017.08.029
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: The phases formed during the hydration of several MgO/SiO2 and Portland cement mixtures were investigated by performing X-ray diffraction and 29 Si and 27 Al solid state NMR experiments on samples hydrated for 1, 7 and 28 days. The structural properties and relative amount of magnesium silicate hydrate (M-S-H) and calcium silicate hydrate (C-S-H) gels, which form as separate phases, were found to significantly depend on the initial composition of the mixtures. Faster hydration kinetics was observed for all mixtures with respect to the "pure" MgO/SiO2 and Portland cement samples, pH and excess of silica playing a major role. Moreover, the addition of the MgO/SiO2 mixture to Portland cement affects the formation of aluminum-containing hydrated phases.