Abstract:
This article presents experimental data on the mineralogical characterization of commercial PC V Portland cement, using X-ray diffractometry (XRD) techniques associated with Rietveld refinement and high-resolution nuclear magnetic resonance spectroscopy of 29Si nucleus (29SiNMR) in solid state, in a sample containing 2.62 % of Fe2 O3 . The anhydrous cement has 66% of calcium silicate phases, 9 % of calcium aluminates, 10% of calcite, 9 % of calcium sulfates, and 6 % of minor phases. In hydrated pastes, it was found that 39.5 % are crystalline phases and 60.5 % are amorphous phases referring to calcium silicate hydrate gels (C-S-H), which is the main product of Portland cement hydration. The data for anhydrous silicates by 29Si-NMR spectroscopy were determined by signs of chemical displacement between -75 ppm and -77 ppm, associated with alite polymorphs, while at -71.3 ppm they refer to belite. At 63 days of hydration, C-S-H was observed in the chemical displacement between -80 ppm and -85 ppm corresponding to Q1 and Q2 sites, respectively. The 29Si-NMR spectroscopy data allowed to detail the amorphous phase generated in the hydration of the cement, being proven that it is C-S-H, which therefore provides structural information before and after the hydration of the cement, and evidences the potential of this technique for application in studies of cementitious materials that, for example, involve the addition of supplementary cementitious materials, whose monitoring of hydration evolution may provide information to understand the degree of reactivity of these cements.
Reference:
NOBRE, Thiago Ricardo Santos; PÉREZ, Martha González; BLOISE JUNIOR, Antoni Carlos.; ÂNGULO, Sérgio Cirelli; OTA, Shoko; QUARCIONI, Valdecir Angelo. Caracterização de fases de cimento Portland por meio das técnicas de difratometria de raios X e espectroscopia de ressonância magnética nuclear de 291SI no estado sólido. Revista IPT, Tecnologia e Inovação, v.6, n.19, p.67-88, maio, 2022.
Access to the article on the Journal website:
http://revista.ipt.br/index.php/revistaIPT/article/view/144/184
This article presents experimental data on the mineralogical characterization of commercial PC V Portland cement, using X-ray diffractometry (XRD) techniques associated with Rietveld refinement and high-resolution nuclear magnetic resonance spectroscopy of 29Si nucleus (29SiNMR) in solid state, in a sample containing 2.62 % of Fe2 O3 . The anhydrous cement has 66% of calcium silicate phases, 9 % of calcium aluminates, 10% of calcite, 9 % of calcium sulfates, and 6 % of minor phases. In hydrated pastes, it was found that 39.5 % are crystalline phases and 60.5 % are amorphous phases referring to calcium silicate hydrate gels (C-S-H), which is the main product of Portland cement hydration. The data for anhydrous silicates by 29Si-NMR spectroscopy were determined by signs of chemical displacement between -75 ppm and -77 ppm, associated with alite polymorphs, while at -71.3 ppm they refer to belite. At 63 days of hydration, C-S-H was observed in the chemical displacement between -80 ppm and -85 ppm corresponding to Q1 and Q2 sites, respectively. The 29Si-NMR spectroscopy data allowed to detail the amorphous phase generated in the hydration of the cement, being proven that it is C-S-H, which therefore provides structural information before and after the hydration of the cement, and evidences the potential of this technique for application in studies of cementitious materials that, for example, involve the addition of supplementary cementitious materials, whose monitoring of hydration evolution may provide information to understand the degree of reactivity of these cements.
Reference:
NOBRE, Thiago Ricardo Santos; PÉREZ, Martha González; BLOISE JUNIOR, Antoni Carlos.; ÂNGULO, Sérgio Cirelli; OTA, Shoko; QUARCIONI, Valdecir Angelo. Caracterização de fases de cimento Portland por meio das técnicas de difratometria de raios X e espectroscopia de ressonância magnética nuclear de 291SI no estado sólido. Revista IPT, Tecnologia e Inovação, v.6, n.19, p.67-88, maio, 2022.
Access to the article on the Journal website:
http://revista.ipt.br/index.php/revistaIPT/article/view/144/184
