Synthesis and characterisation of magnesium silicate hydrate gels

• Published in: Cement and concrete research Vol. 35; no. 1; pp. 85 - 98
• Main Authors: Brew, D.R.M., Glasser, F.P.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 2005; Elsevier Science
• Subjects: 29Si NMR, FT-IR; Analysis of cement phases and constituents; Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Exact sciences and technology; Gel structures; Materials; MgO–SiO 2–H 2O gels; MgO–SiO 2–H 2O minerals; Properties of anhydrous and hydrated cement, test methods; MgO–SiO 2–H 2O gels; MgO–SiO 2–H 2O minerals; 29Si NMR, FT-IR; Gel structures; Chemical analysis; MgO-SiO2-H2O gels; MgO-SiO2-H2O minerals; 29Si NMR; Magnesium oxide; Inorganic synthesis; Experimental study; Electron microscopy; FT-IR; Gel structures; Portland cement; X ray diffraction; Characterization; Infrared spectrometry; Magnesium silicate; Nuclear magnetic resonance; NMR spectrum; Freeze; Hydrates
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2004.06.022

Magnesium silicate hydrate gels (M-S-H) have been prepared by precipitation. The range of gel compositions lie between Mg/Si molar ratios 0.67–1.0. The gels were subject to short cure, approximately 24 h at approximately 22 °C and longer cure, 180 days at 85 °C, following which they were characterised by XRD, FT-IR and solid-state 29Si NMR. Ageing at longer times and higher temperatures somewhat improves the local ordering. The nature of the partially ordered structures is related to those of M-S-H mineral phases. The structures and compositions of M-S-H gels differ from those of C-S-H gels and partly on that account, C-S-H gels contain little magnesium while M-S-H gels in blended cements coexist with C-S-H but contain little calcium.