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Concrete with fly ash for XF3 and XF4
Máša, Jiří ; Ťažký, Martin (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with concrete using fly ash as an active ingredient for environment XF3 and XF4. Bachelor thesis is divided into two parts. The first, theoretical part, is focused on basic information on power generation of fly ashes and solves the existing knowledge about concrete with partial asphalt replacement and then evaluates their properties both in fresh and condensed state. Below are the world-wide knowledge of the behavior of these concrete. The second part deals with the experimental verification of these findings contained in the theoretical part. The aim of this work is to verify the durability of concrete with fly ash for XF3 and XF4 environments.
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Study of the concept of K-value and efficiency index for fly ash and slag and their assessment and determination for concrete
Šperling, Petr ; Hela, Rudolf (referee) ; Hubáček, Adam (advisor)
This bachelor thesis deals with the use of active admixtures as a substitute for cement in concrete, specifically power plant fly ash and blast furnace slag. When using power plant fly ash and blast furnace slag as a substitute for cement in concrete, it is necessary to know their effect on concrete and to assess the different properties compared to concrete in which these admixtures are not used. This work will summarize the existing knowledge of the properties of power plant fly ash and blast furnace slag and their effect on fresh and hardened concrete. Furthermore, the possibilities of determining the efficiency index and the so-called k-value concept, which are used to assess the effect on cement mortar and concrete when replacing cement with an active admixture, will be summarized. In the experimental part, emphasis will be placed on determining the k-value. This is described in European technical standards in a very general way and is not sufficiently detailed for specific active ingredients.
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Optimizing the use of active admixtures in mixed cements and determining the k value
Kužílková, Hana ; Hubáček, Adam (referee) ; Hela, Rudolf (advisor)
The goal of this bachelor's thesis is to examine the possibility of using admixtures as a partial substitute for cement in concrete. The thesis examines the replacement of cement with three specific additives: micronized limestone, power plant fly ash and blast furnace slag. When using an admixture as a partial replacement for cement, the addition of the admixture affects the properties of both fresh and hardened concrete. The theoretical part of the work is devoted to the description of admixtures and their influence on the properties of fresh and hardened concrete. Furthermore, basic information on the efficiency index and k-value is presented. The aim of the practical part of the bachelor's thesis is to determine the efficiency indices of the given additives as well as their k-values.
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Algebraic proofs of Dirichlet's theorem on arithmetic progressions
Čech, Martin ; Kala, Vítězslav (advisor) ; Příhoda, Pavel (referee)
Dirichlet's theorem on arithmetic progressions says that there are infinitely many primes in any arithmetic progression an = kn + with coprime k, . The original proof of this theorem was analytic using a lot of non-elementary methods. The goal of this thesis is to give sufficient and necessary conditions on k and under which a more elementary algebraic proof of the theorem can exist, and give the proof in these cases. 1
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Study of possibilities of activation of power plant fly ash as an active ingredient in concrete
Máša, Jiří ; Uher, Vojtěch (referee) ; Hela, Rudolf (advisor)
Global concrete production is increasing, which brings some environmental burden. A certain solution is the use of secondary raw materials, which has been a long-standing practice in the construction industry. One of the most widespread secondary raw materials is power fly ash. However, in recent years trends have been directed towards maximizing their utility properties. The aim of this work was to study the possibilities of activation of power plant fly ash as an active admixture in concrete. The thesis is divided into two parts, the theoretical and the practical part. The theoretical part describes in detail the possibilities of power plant fly ash activation for use as an active admixture in concrete. The practical part of the thesis is focused on mechanical activation, where the knowledge of the theoretical part is verified on various fly ash.
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The development of high-strength concrete with a high content of el. fly ash
Roubal, David ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with the study of high-strength, high-volume fly ash concrete. The theoretical part of this thesis focuses on the detailed characteristic and main principles of high-strength concrete, high-volume fly ash concrete. In addition, according to the findings, the technology of high-strength and high-volume fly ash concrete, including principles of high strength, has been described. On the basis of the findings, high-strength, high-volume fly ash concrete for specific compressive strengths has been designed and created in the experimental section. These concretes were then subjected to a number of tests.
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Monitoring the influence of concrete composition on abrasion resistance
Černá, Hana ; Novosad, Petr (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis focuses on the resistance of concrete to abrasion with regard to the raw materials used for their production. In the theoretical part of the thesis are described admixtures, different types of aggregate and aggregate composition which influence the resistance of concrete to abrasion. In the experimental part, 15 different C30 / 37, S4 concrete formulations were proposed. Different types of aggregates - fecal gravel (Žabčice), biotic granodiorite (Olbramovice) and amphibolite (Želešice) have always been used in the recipes. Fine ground limestone, micro-silica, high-temperature fly ash and finely ground slag were ingredients that were added to the proposed recipes. Consistency was determined by the method of cone seating and the density of fresh concrete. In the hardened state, concrete density, compressive strength, bending tensile strength, tensile strength, watertightness, concrete absorption, and abrasion resistance were determined using the Böhm method and wide wheel method. The test specimens were tested after 7, 28, and 90 days of maturation.
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Concrete with fly ash for XF3 and XF4
Máša, Jiří ; Ťažký, Martin (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with concrete using fly ash as an active ingredient for environment XF3 and XF4. Bachelor thesis is divided into two parts. The first, theoretical part, is focused on basic information on power generation of fly ashes and solves the existing knowledge about concrete with partial asphalt replacement and then evaluates their properties both in fresh and condensed state. Below are the world-wide knowledge of the behavior of these concrete. The second part deals with the experimental verification of these findings contained in the theoretical part. The aim of this work is to verify the durability of concrete with fly ash for XF3 and XF4 environments.
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Design and development of the electrostatic precipitator
Kvasnička, Karel ; Radil, Lukáš (referee) ; Ptáček, Michal (advisor)
This bachelor thesis deals with the design of an electrostatic precipitator and familiarization with the problems of separation on these separators. The aim of this work is to construct a functional model of an electrostatic precipitator. The principle of operation and design will be described. In addition, the design of a separator is elaborated, which was subsequently realized and experimentally verified in the CVVOZE Power Laboratories Research Infrastructure. The first part deals with the description of the legislation on air protection, the most frequent input material of separators and descriptions of the basic types of separators. In addition, the electric separator, its area of use, construction and individual components, as well as the undesirable operating state of the separator, are further elaborated. In the second part are presented the equations and calculations for the design of the separator. In the next part, the separator designer and his laboratory tests are described. The separator was subjected to basic voltage tests from the viewpoint of its operating voltage. Its functionality fits the realized experiments up to 30 kV. On the basis of this work and the production of the equipment, it is possible in the future to test the properties of flue gases and other gases.
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Algebraic proofs of Dirichlet's theorem on arithmetic progressions
Čech, Martin ; Kala, Vítězslav (advisor) ; Příhoda, Pavel (referee)
Dirichlet's theorem on arithmetic progressions says that there are infinitely many primes in any arithmetic progression an = kn + with coprime k, . The original proof of this theorem was analytic using a lot of non-elementary methods. The goal of this thesis is to give sufficient and necessary conditions on k and under which a more elementary algebraic proof of the theorem can exist, and give the proof in these cases. 1
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