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Thermodynamic Stability of Thaumasite
Pospíšilová, Klára ; Dvořák, Karel (referee) ; Fridrichová, Marcela (advisor)
This work deals with the resolution of the identification characteristics of the thaumasit, which falls into the same group of AFt phases as the mineral ettringit. Both of these stages have the same structural arrangement and the morphology. This work’s specific goal is the synthetic preparation of thaumasit in a variety of conditions and its evaluation.
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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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Development of phase composition in silicate systems by available methods and their optimalization
Opravilová, Lenka ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
One of the most prominent measurable parameters of the development of phases and phase transformations in inorganic systems are undoubtedly the volume changes of silicate matrix. The study of volume changes is crucial in the terms of usable durability of final product. They represent shrinkage or expansion of the material and may lead to significant decrease of technological and ecological parameters and often to complete destruction of these materials. Most often the volume changes can be observed when cement is used as a binder and in concretes, mortars, artificial aggregates and other similar materials. There are many methods to detect, define and determine the volume changes qualitatively or quantitatively. The development of phases was investigated as a part of the dissertation thesis and hence the volume changes were observed under the conditions closest to the real state in the construction industry. The raw materials and admixtures were selected which model the content of hazardous components present in conventional materials (both natural and secondary), used in construction and the relationship with volume changes was searched and demonstrated. The contacts for measuring the volume changes were attached to test surfaces of specimens and the physical - mechanical tests (volume changes, phase changes, strength, etc.), chemical analysis and ecotoxicity tests depending on the length of hydration were performed.
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Study of Preparation and Properties of Historic Mortars
Majerová, Jana ; Lang,, Karel (referee) ; Fridrichová, Marcela (advisor)
The diploma thesis is concerned with study of preparation and properties of historic mortars. In theoretical part, there is summarized the historic progress of mortars and their material composition. The experimental part is focused on proposition of mortar mixes. The diploma thesis referring to actual research on Institute of Technology of Building Materials and Components, FCE VUT in Brno. The base mixe of historical mortar came from this research. In experiment, there is the base mixe of historical mortar modified with gypsum. In the first phase of the experimental part the basic technological and aplication properties are assessed. The second phase of the experimental part is focused on the course of hydration of the binder in different environments and subseqeunt determination of the phase composition by X-ray diffraction analysis. The aim of the thesis is to determine the optimal amount of gypsum and to optimize the recipe of historical mortar.
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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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Study of durability of binders concept on purposeful creation of ettringite
Sokolt, Stanislav ; Štenko,, Miroslav (referee) ; Žižková, Nikol (advisor)
This master thesis is focused on the binary and ternary systems with connective purposeful ettringite formation for fast hardening adhesive for ceramic tiles. It deals with the durability of these materials after exposure to the corrosive environment. It examines the physical and mechanical properties and mineralogy changes after exposure to corrosive environments. Within processing of this paper provides basic information concerning the connective concept of purposeful formation of ettringite.
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