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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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Long-term durability of composite restoration margins in environments with increased corrosion risk
Roubíčková, Adéla ; Bradna, Pavel (advisor) ; Veverka, Jan (referee) ; Halačková, Zdena (referee)
Introduction: An adhesive bond between hard dental tissues and composite reconstructions is exposed to mechanical load, water, bacteria, enzymes and different chemical compounds. These factors could impair durability and resistance of composite reconstructions. In contrast with extensive research of negative influence of water on degradation of adhesive bonds, the influence of chemical substances on adhesive bond has not been investigated to a greater extent. Aim: The aim of the experimental part of the thesis was to evaluate the influence of hydrogen peroxide containing tooth-whitening products and mouth rinses containing chlorhexidine and fluoride on a long-term stability of class V composite restorations created using four contemporary adhesive systems by a microleakage method. Materials and methods: The following adhesive systems were investigated: total-etch Gluma Comfort Bond (GLU), and self-etch adhesives Clearfil SE Bond (CLF), Adper Prompt (ADP) and iBond (IBO). Standardized class V cavities were prepared in 192 extracted human teeth (one cervical margin in the cementum and one in the enamel). Subsequently, the cavities were restored using microhybride composite Charisma. The specimens were then exposed to the tooth whitening system Opalescence PF 20, mouth rinse Corsodyl containing...
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Durability of repair materials with higher fire resistance for concrete structures
Počekajlo, Václav ; Dohnálek,, Pavel (referee) ; Bydžovský, Jiří (advisor)
This dissertation deals with the study of durability and degradation repair mortars for reinforced concrete structures. In its theoretical part, there are the research findings on the behavior of repair mortars exposed to corrosive environments with different exposure time and selected high temperatures. Processes occurring in repair mortars during their loading at high temperatures or when exposed to chemically aggressive environments are described, We can find recipes designed for cementitious binder based with a specific replacement using slag or fly ash in its practical part. The object of the research was to determine the durability of the proposed repair mortars, and determine their suitability for use on concrete structures, which may be exposed to a synergistic effect of chemically aggressive environments with high temperatures simulating fire.
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Effect of acidic influence on the refractory castable with different cement content.
Mátl, Daniel ; Henek,, Milan (referee) ; Nevřivová, Lenka (advisor)
There are applications of refractory concretes for places where these are exposed to corrosive environments. This diploma thesis deals with both description the corrosive effects and methodology of their testing. One of the most important properties of materials, affecting the chemical corrosion resistance, is their density. The practical part of the thesis is focused on testing the refractory concretes which are currently used for applications. The aggregates were tested for the resistance to sulfuric acid.
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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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Assessment of physico-mechanical properties and durability of binder concepts based on purposeful creation of ettringitu
Pupíková, Petra ; Štenko, Miroslav (referee) ; Žižková, Nikol (advisor)
Masters`s thesis deals with study of binder concept based on purposeful creation of ettringite, assessment of physic-mechanical properties and durability. The teoretical part is the mention of ettringite and his function in building materials, are described binder concepts based on purposeful creation of ettringite and self-levelling screed for which the controlled formation ettringite typical. In the practical part are did analysis of raw materials and the composition of the mixture, including types corrosive environment for the assessment of durability. In addition are checked properties of the proposed mixture and evaluated the appropriateness of use of each type of waste materials with regard to the resulting properties.
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Assessment of resistance castables to chemically aggressive environments.
Mátl, Daniel ; Henek,, Milan (referee) ; Nevřivová, Lenka (advisor)
There are applications of refractory concretes for places where these are exposed to corrosive environments. This bachelor thesis deals with both description the corrosive effects and methodology of their testing. One of the most important properties of materials, affecting the chemical corrosion resistance, is their density. The practical part of the thesis is focused on testing the grogs which are currently used for production of refractory concrete. The aggregates were tested for the resistance to sulfuric acid.
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Metody ochrany karoserií vozidel proti korozi
Hána, Daniel
This thesis deals with corrosion and corrosion resistance of steel parts of motor vehicles. First part describes in depth general issues of degradation corrosion systems, with emphasis on clear classification of corrosion types and anti-corrosion treatments. The next part defines particular anti-corrosion treatments. This part is followed by a concrete description of coachwork anti-corrosion treatment. Here the attention is paid to those anti-corrosion treatments that are currently most used by leading motor vehicles manufacturers.
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