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Long-term tests for examination of surface treatments in various adverse environments simulating real effects
Hudečková, Petra ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
Cement bonded particleboards contain organic base and as they are set outside, extreme weather condition, such as frost, chemical defrosting substances or sulphates, cause their degradation. The presence of the organic base in the matrix of the material could be the reason why there is higher probability of degrading when compared with materials containing an inorganic base. It could be partially eliminated by an appropriate surface modification of the slab, which main goal is to weaken the impact of an aggressive environment and to extend the lifespan of the board. On the other hand, the surface modifications based on a polymer base are prone to degrade because of other unfavourable conditions such as UV radiation when compared with the cement bonded particleboard. The classification of the surface modifications and the way of their degradation caused by the aggressive environment in real applications are presented in the theoretical part of the thesis. In the experimental part, appropriate methodical ways of testing the resistance of cement bonded particleboard’s coating system were chosen. Then, the testing and comparing of the physical, mechanical and aesthetic properties of different types of coatings were done. Moreover, a spectrophotometric analysis of the colour shade changes for the different aggressive environment were carried out. Furthermore, microstructures of chosen surface modifications were assessed by using an optical and an electron microscope.
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Study of FRP for concrete reinforcement
Blahová, Aneta ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis aims to analyze bent FRP reinforcements. It describes the method of production of bent FRP reinforcement, examples of application of FRR reinforcement in structures and mentions aggressive influences influencing the durability of FRP reinforcement. Furthermore, an experiment is proposed to monitor changes in straight and bent FRP reinforcement stored in an aqueous environment at 20 °C and an alkaline environment at 20 °C and 40 °C. The output of the diploma thesis is the evaluation of changes in mechanical properties and durability. The condition of the FRP reinforcement is documented using optical and electron mocroscopy.
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Possibilities of using Crystallization and sealing Admixtures for Concrete in a highly chemically aggressive Environment
Fittl, David ; Slezák, Viktor (referee) ; Hubáček, Adam (advisor)
Previously neglected and today largely run-down agricultural and farm buildings, which have not been properly maintained, are in a dilapidated state. In recent years, however, farmers and husbandmen have been trying to create a greener and more sustainable environment. Therefore, construction companies and concrete manufacturers are under pressure to produce more resistant concrete structures with enhanced durability for buildings that must withstand aggressive environments. This thesis summarizes the current knowledge of the durability of concrete exposed to highly chemically aggressive environments; it provides a summary of the knowledge of individual types of crystallization additives in concrete; and it includes descriptions of the various types of environment affecting concrete and descriptions of agricultural and farm buildings.
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Possibilities of increasing durability of concrete in highly chemical aggressive environment in agriculture
Sláma, Radek ; Slezák, Viktor (referee) ; Hubáček, Adam (advisor)
In recent years there has been a significant increase in the production of concretes for agricultural buildings, especially in the area of exposure to higly chemically aggressive environments. The aim of the thesis is to describe and summarize the existing knowledge about the durability of concrete exposed to the effects of highly chemically agressive environment. Furthermore, emphasis is placed on the description of individual additives and admixtures increasing the resistance of concrete to the effect of harmful substances. In the experimental part, the effects of individual types of additives, admixtures and sealing coatings on increasing the resistance of concrete against the effect of highly chemically aggresive environment are investigated in the laboratory.
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Study of properties of Fiber-Reinforced Polymers
Fojtášek, Martin ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Bachelor thesis deals with monitoring the properties of the FRP reinforcement when exposed to aggressive environments that cause degradation. In the theoretical part of this thesis there are described the method of production, the most commonly used types of FRP profiles, the composition of the FRP profiles, durability of FRP profiles against the action of aggressive environment and durability of the FRP material in the damage environment. Further more there are briefly described the most common types of tests on FRP profiles. In the experimental part of this thesis there are defined conditions for laboratory testing of FRP samples, which were stored in an alkaline environment at temperatures of 20 degrees, 40 degrees and 60 degrees. These samples of the FRP were stored and tested after 90 days. Subsequently there are described the changes of the physical properties of rebar in a time when saving in an aggressive environment.
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Corrosion of Aircraft Structures
Poláček, Juraj ; Juračka, Jaroslav (referee) ; Katrňák, Tomáš (advisor)
Presented bachelor's thesis deals with the corrosion attack of aircraft structures and their influence on the mechanical properties of individual parts of aircraft structures. The research part of the thesis describes the principles of corrosion attack formation and the influence of aggressive envi- ronments on their formation and development. The influence of aggressive environments is demonstrated through corrosion tests. The thesis maps the most commonly used materials in the aerospace industry. At the same time, it assigns specific materials to typical locations of aircraft structures. Through information and assistance with LOM Prague company, the thesis identifies and displays the most common corrosion-prone areas. Additionally, possible hazards arising from corrosion in specific locations of aircraft structures are described. The output of the thesis presents options for corrosion protection. This is especially the process of anodization, surface treatments, maintenance and appropriate material design in the development of aircraft structures. Due to the extensive use of the anodization process and surface treatments, an analysis was conducted to assess their impact on the mechanical properties of aluminium alloy 6061.
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Study of FRP for concrete reinforcement
Blahová, Aneta ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis aims to analyze bent FRP reinforcements. It describes the method of production of bent FRP reinforcement, examples of application of FRR reinforcement in structures and mentions aggressive influences influencing the durability of FRP reinforcement. Furthermore, an experiment is proposed to monitor changes in straight and bent FRP reinforcement stored in an aqueous environment at 20 °C and an alkaline environment at 20 °C and 40 °C. The output of the diploma thesis is the evaluation of changes in mechanical properties and durability. The condition of the FRP reinforcement is documented using optical and electron mocroscopy.
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Possibilities of increasing durability of concrete in highly chemical aggressive environment in agriculture
Sláma, Radek ; Slezák, Viktor (referee) ; Hubáček, Adam (advisor)
In recent years there has been a significant increase in the production of concretes for agricultural buildings, especially in the area of exposure to higly chemically aggressive environments. The aim of the thesis is to describe and summarize the existing knowledge about the durability of concrete exposed to the effects of highly chemically agressive environment. Furthermore, emphasis is placed on the description of individual additives and admixtures increasing the resistance of concrete to the effect of harmful substances. In the experimental part, the effects of individual types of additives, admixtures and sealing coatings on increasing the resistance of concrete against the effect of highly chemically aggresive environment are investigated in the laboratory.
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Possibilities of using Crystallization and sealing Admixtures for Concrete in a highly chemically aggressive Environment
Fittl, David ; Slezák, Viktor (referee) ; Hubáček, Adam (advisor)
Previously neglected and today largely run-down agricultural and farm buildings, which have not been properly maintained, are in a dilapidated state. In recent years, however, farmers and husbandmen have been trying to create a greener and more sustainable environment. Therefore, construction companies and concrete manufacturers are under pressure to produce more resistant concrete structures with enhanced durability for buildings that must withstand aggressive environments. This thesis summarizes the current knowledge of the durability of concrete exposed to highly chemically aggressive environments; it provides a summary of the knowledge of individual types of crystallization additives in concrete; and it includes descriptions of the various types of environment affecting concrete and descriptions of agricultural and farm buildings.
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