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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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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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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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Assessment of degradation of coatings for cement composites with organic fillers due to aggressive environments
Pernicová, Kateřina ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
There are many methods and techniques for assessing the degradation rate of coatings for cement composites with organic fillers. However, it is necessary to choose appropriate combination of various adverse conditions including intensity level of corrosive media and duration of action of these compounds on the material to simulate their complex effect in relation to the real exposure of structures. Part of the theoretical work is focused on the kinds of coatings that are suitable for cement composites with organic fillers and then there are listed devaluing environments which these coatings affect. There is also a proposal for a testing a complex simulation of a real environment. The practical part describes the tests that were performed on cement bonded particleboards with applied coatings.
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