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Study of ettringite stability depending on external conditions
Pekárková, Jana ; Brauner,, Josef (referee) ; Durica,, Tibor (referee) ; Bílek,, Vlastimil (referee) ; Gazdič, Dominik (advisor)
The doctoral thesis was focused on the study of thermodynamic stability of ettringite. Ettringite was first prepared in two different ways and then exposed in chosen environments. Furthermore, the stability of ettringite in interaction with calciumsilicates was investigated. As ettringite can be formed as a hydration product of fluidized bed fly ash, the properties of Portland fly ash cement in comparison with Portland cement and Portland slag cement were investigated at the end of the thesis.
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Study of the properties of the ettringite which was produced synthetically
Hučínová, Lenka ; Jiroušková, Kateřina (referee) ; Fridrichová, Marcela (advisor)
Up to present, ettrigite has been prepared by two means in the Institute of Technology of Building Materials and Components of the BUT Faculty of Civil Engineering: originally by the hydration of the yeelimite clinker; recently by the direct synthesis of ettringite from calcium hydroxide and aluminum sulfate, the latter being considered more suitable in qualitative and quantitative terms. This diploma thesis focuses on the comparison of both means, using ettringite produced by the latter as control sample. This endeavor focuses on monitoring the stability of ettringite and its possible conversion to other minerals using X-ray diffraction analysis, thermal analysis and scanning electron microscopy (SEM).
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Synthetic Preparation and Properties of Ettringite
Vlachovský, David ; Kulísek, Karel (referee) ; Fridrichová, Marcela (advisor)
The work is focused on properties and behavior of ettringite in relation to external environment conditions. It concentrates on the mineralogical composition of ettringite prepared by the method of direct synthesis of aluminium sulphate octadecahydrate and calcium hydroxide at various humidities. Depending on these factors, the formation of ettringite and its possible conversion to other minerals was observed.
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The thermodynamic stability of etringite
Magrla, Radek ; Durica,, Tibor (referee) ; Bílek,, Vlastimil (referee) ; Brauner,, Josef (referee) ; Fridrichová, Marcela (advisor)
The theoretical part of this doctoral thesis summarizes the current knowledge of portland cement and its manufacturing technology, information of FBC ash, Aft phases, AFm phases and the current knowledge of thermodynamic stability of ettringite. The practical part of the doctoral thesis focuses on manufacturing of ettringite based on yeelimite clinker, studying the influence of environment on thermodynamic stability of ettringite and manufacturing of ettringite by direct addition of calcium hydroxide and aluminum sulfate.
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