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Experimental research of suitability and durability of sealants used in civil engineering
Hanzelková, Martina ; Schmid, Pavel (referee) ; Sedlák,, Petr (referee) ; Šlanhof, Jiří (advisor)
The dissertation thesis is focused of the method of testing the building sealnats. This is a summary of the research focused on the evaluation of sealants in interaction with the underlying materials. Attention is focused on the official test methods contained in European technical standards, the benefits of individual methods, their advantages and disadvantages are discussed. Also included are the overall findings of the practical application of the test procedures applied to 10 commercially available industrial sealants on 8 different substrates, including facade lining boards used for lightweight envelope systems. The dissertation thesis contains general conclusions about individual test methods. The research also includes various ways of preparing and conditioning test specimens that simulate different environmental conditions and, in some cases, play a crucial role in the final evaluation of sealants.
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The development of composites based on inorganic binders designed for the extreme applications
Janoušek, Petr ; Šácha, Libor (referee) ; Dufka, Amos (advisor)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
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Bond between FRP reinforcement and concrete
Januš, Ondřej ; Hradil, Petr (referee) ; Materna, Alois (referee) ; Štěpánek, Petr (advisor)
Recently, FRP (fibre reinforced polymers) materials are increasingly used in concrete structures, both for the strengthening of existing structures and as an internal reinforcement of concrete elements. It is due to convenient mechanical and physical properties of this kind of material. However, the use of these innovative materials as a reinforcement of concrete structures often requires a modification of the design process used for steel reinforcement. At present, a large number of bridge structures are in a very poor condition and require remediation due to corrosion of the steel reinforcement. Composite reinforcement appears to be a suitable alternative to steel reinforcement in these application areas. However, since bridge decks are directly exposed to repeated traffic loads, fatigue assessment is an important and often crucial part of the design. The number of studies dealing with the fatigue behaviour of internal FRP reinforcement is currently very limited. In particular, there is currently no study that sufficiently deals with the comprehensive determination of the effect of fatigue loading on the bond between FRP reinforcement and concrete. The doctoral thesis deals with the design of concrete elements reinforced with modern composite FRP reinforcement exposed to high-cyclic (fatigue) loading. Thanks to the performed extensive experimental programme, it was possible to determine the permissible limit values of fatigue load to ensure the required fatigue life. Based on these limiting values, the design and subsequent fatigue testing of full-scale concrete roofing slabs intended for aggressive environments was performed.
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NATO and the EU's strategic communication's cohesion from the perspective of the ritual model
Dušková, Lenka ; Karásek, Tomáš (advisor) ; Kučera, Tomáš (referee)
At the core of this master thesis lies the cohesion of NATO and the EU's strategic communication. The cohesion is researched in the context of both institutions' reactions to hybrid threats from quantitative and qualitative points of view. The thesis observes communication's cohesion within the realm of NATO and the EU's responses to the annexation of Crimea and subsequent war in Ukraine, the Skripals' poisoning, and the instrumentalization of migration by the Belarusian regime. What precedes the empirical part is a summary of current academic debates about the concept of strategic communication and also the description of NATO and the EU's communication systems. The analysis then builds on the extensive dataset of NATO and the EU's event-related messages. The intrainstitutional and interinstitutional cohesion is assessed based on the frequencies and timing of the messages in the above- mentioned cases. The subsequent qualitative analysis draws on Carey's proposed ritual view of communication. It further analyzes whether the content of NATO and the EU's strategic communication reflects their core values, threat perception, narratives about expected appropriate behavior, visioning, and whether it refers to the common historical experience, stimulates a shared view of reality, and explicitly...
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Climate of a school class
Zelenková, Blanka ; Linková, Marie (advisor) ; Blažková, Veronika (referee)
The aim of bachelor's thesis is to find out and compare the climate of two 6th (later 7th ) grade classes at the elementary school.The paper deals with deterioration of discipline, study results and hard work of teachers in these classes. The teoretical section defines the basic terms - climate, actors of climate, types of climate, approaches to studying climate and its measurement, social interaction. Practical part introduces the method MCI, then it describes the research and its progress. In the final part of the thesis marked out assumptions are verified.
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The Activity of European Peoples Party in The European Parliament. The Challanges and The Perspectives
Málek, Jan ; Rovná, Lenka (advisor) ; Škrábalová, Lenka (referee)
Text of the thesis focuses on the activity of the Group of the European People's Party in the European Parliament. It focuses on this issue from three different perspectives. The first perspective presents a theoretical approach on the concept of europarty as transnational political actor that has developed on the basis of the development of the European integration and the development of the European institutions. The second perspective focuses on the work of the European People's Party, as a classic example transnational European party structure. It refers to its historical development and formation in the context of strengthening the position of the European Parliament. It also encompasses the Group of the European People's Party and its influence in the European Parliament in historical perspective. At the same time reveals the inner structure, program policies and operation mechanism of this parliamentary faction. The third perspective focuses on the analysis of the cohesion of the Group of the European People's Party in the seventh term of the European Parliament. The group cohesion is viewed as one of the main characters determining the strength and importance of the parliamentary factions. The analysis is based on the theoretical assumptions of British political scientist Simon Hix. In...
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Tensional Properties of Sealants in Cement-Based Material Sealing
Boháček, Adam ; Brandtner, Michal
The article deals with sealing of cement-based materials and tensile properties of the sealed joint. Aquapanel cement board was chosen as the base material, which was treated with a primer. Then two sealants were applied, one representative of acrylic and one of polyurethane sealants. After curing, the resulting test specimens were tested according to the valid European standard ČSN EN ISO 8340, which defines the parameters of the test specimen and subsequent test procedures. The evaluation of the test, which took place visually and with a caliper measurement, showed that only polyurethane sealant could be recommended for sealing Aquapanel. This putty, unlike acrylic putty, did not show any defects after the test, so it can be stated as suitable for sealing Aquapanel cement board.
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FRP for concrete reinforcement
Blahová, Aneta ; Vaněrek, Jan (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with composite polymer FRP reinforcement. It descibes the method of manufacturing FRP reinforcements, which are their properties and what materials are used by manufacturers. Lists FRP reinforcement application in various structures. Also mentions the durability of FRP reinforcement in an aggressive environment and the cohesiveness of FRP reinforcement with concrete. The conclusion of the work is a proposal for experimental testing of a bond between FRP reinforcement and concrete.
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