The influence of calcium formate on the hydration of calcium sulfate hemihydrate

被引：0
作者：
Nicholas Fobbe
Friedlinde Goetz-Neunhoeffer
Daniel Jansen
机构：
[1] Friedrich-Alexander-Universität Erlangen-Nürnberg,
[2] GeoZentrum Nordbayern,undefined
[3] Mineralogy,undefined
[4] Schlossgarten 5a,undefined
来源：
Materials and Structures | 2023年 / 56卷
关键词：
Gypsum plaster; Calcium formate; Hydration; Retardation; Adsorption;
D O I：
暂无
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学科分类号：
摘要：
In this study, the influence of calcium formate (CF) on the hydration of a synthesized calcium sulfate hemihydrate (HH) powder was investigated. Isothermal calorimetry measurements showed that CF retards the hydration reaction of HH. This was confirmed by XRD of stored samples and pore solution analysis. Two retardation mechanisms were identified. The combination of pore solution and laser granulometric experiments revealed that firstly, the initial dissolution of hemihydrate decelerates because of high Ca2+ ion concentrations, donated by the faster dissolving CF. Secondly, the HCOO− species of CF adsorb on surfaces of the gypsum crystals, as further pore solution measurements showed. This impedes their formation kinetic. The gypsum crystals exhibited anisotropic peak narrowing in XRD measurements when CF was added. This was caused by a morphology change, which could be verified using the anisotropic domain size morphology approach during Rietveld refinement analysis and SEM images. Gypsum crystals exhibit a blockier shape with CF addition compared to the usual acicular shape in pure water.
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  • [11] Escalante-García JI(2009)Effect of calcium formate as an accelerator on the physicochemical and mechanical properties of pozzolanic cement pastes Cem Concr Res 117 165-176
  • [12] Gorokhovsky A(1995)The effects of calcium formate on the early hydration of alkali silicate activated slag J. Solid State Chem. 36 2881-2890
  • [13] Lanzón M(1980)Cohesion and expansion in polycrystalline solids formed by hydration reactions—the case of gypsum plasters B Struct Crystallogr Cryst Chem 83 79-85
  • [14] García-Ruiz PA(2016)Investigation of the crystal structure of γ-CaSO Cem Concr Res 41 602-608
  • [15] Myrdal R(2011), CaSO Cem Concr Res 53 119-126
  • [16] Heikal M(2013), 0.5 H Cem Concr Res 48 189-194
  • [17] Jin Y(2015)O, and CaSO J Appl Crystallogr 107 247-252
  • [18] Stephan D(2018), 0.6 H Cem Concr Res 48 1998-2001
  • [19] Lu Z(2015)O by powder diffraction methods J Appl Crystallogr 32 S27-S34
  • [20] Gartner EM(2017)Charge density in anhydrite, CaSO Powder Diffr 49 3341-3367
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