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Mortar with alkali-activated matrix
Černá, Hana ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis addresses the issue of alkali-activated materials and their manufacturing components. In the theoretical part the description of such materials is provided and the requirements for source materials are defined. The theoretical part further addresses the resistance of alkali-activated materials and their lifespan - namely sulphate resistance, chloride resistance, acid resistance, frost resistance, porosity, carbonation, resistance, abrasion resistance and heat resistance. The experimental part of the thesis focuses on compounding four different mixtures of alkali-activated materials. In the loosened stage, the weight was measured. In the hardened stage the weight was measured as well as the tensile strength when bending, the strength under pressure applied, heat resistance, water and defrosting chemicals resistance and formation of cracks.
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Monitoring the Influence of ceramic bond on the properties of insulating refractory materials
Friček, Jakub ; Kovář,, Pavel (referee) ; Nevřivová, Lenka (advisor)
Thermal insulating refractories are an integral part of each thermal unit since they reduce its energy consumption. The current phenomenon of saving in both environmental and financial aspects reflects in searching for such possibilities to produce at lower manufacturing and material costs. One of the possible ways is to valorise waste materials. The theoretical part then deals with the division of refractory materials, classification of thermal insulation refractory materials and manufacturing technologies. The experiment is focused on the production of insulating refractory materials made from plastic dough with a possibility of using sawdust and materials made by pressing mixture moist, with a focus on coal bottom ash. Both of these technologies will be tested for the possibility of modification by using mixed clays and of increasing the strength by using clays with lower sintering temperature.
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Study utility properties of heat-reflective insulation for the buildings
Rauchfussová, Karolína ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
Presented work deals with the study progressive heat-reflecting foil thermal insulating materials and defines their thermal insulation properties. The work describes a transport mechanism of thermal energy in the structure of heat-reflecting materials, their physical properties, especially heat resistance, compared to the conventional thermal insulating materials available on Czech market. The main applications ways and installation methods of these materials (especially in low-energy and passive buildings) are also shown. The practical part is focused on asembling the measuring device HOT BOX in accordance with the valid standards, to determine the heat resistance of heat-reflecting materials. In next step the measurement of reflection of aluminum foils (an integral part of the structural arrangement heat-reflecting foil insulations) was performed.
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The Effect of Sawdust on the Refractoriness of Insulation Chamotte
Smékalová, Veronika ; Kotásek, Martin (referee) ; Sokolář, Radomír (advisor)
Lightweight refractory products have their place between refractory materials. Still the most common way of lightweighting is by using burnable components. This bachelor work includes the theoretical part, which deals with raw materials for lightweight fireclay, manufactory, and also testing lightweight refractory products. The second part of this work deals with foreign research and its results in this area. The practical part examines the influence of the types of sawdust (spruce or beech) on properties of lightweight refractory materials. The work focuses mainly on heat resistance, temperature usability, thermal conductivity, and density. These properties are evaluated with consideration to the ash which is created by burning sawdust.
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Development of polymer repair materials using secondary raw materials
Juřička, Viktor ; Vyhnánková, Michaela (referee) ; Drochytka, Rostislav (advisor)
The diploma thesis deals with the development of polymeric repair mortars in two qualitative levels ECONOMY and PREMIUM, designed especially for heavy engineering plants and the energy industry. In order to effectively withstand difficult industrial conditions, the developed materials should meet the highest requirements such as increased chemical and heat resistance, excellent adhesion to the concrete substrate, minimal shrinkage and other physical and mechanical properties. The PREMIUM level is aimed to achieve maximum physical and mechanical properties. Within the economy version, the emphasis is placed not only on very good properties, but also the possibility capability of reducing price of the resulting material. The partial aim of this work is the efficient use of secondary raw materials, mainly based on industrial waste in the form of fillers to the developed polymeric repair mortars.
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Study of resistance of selected aggregates to high temperatures
Holanec, Aleš ; Sitek,, Libor (referee) ; Bodnárová, Lenka (advisor)
The thesis deals with the monitoring of changes taking place in natural stones and aggregates under high temperatures. The theoretical part of the work provides information about basic groups of rocks, the technology of processing the natural stone and primarily about the study of behavior of natural stone and aggregates at high temperatures. Also some findings from different research works aimed at monitoring the behavior of rocks at high temperatures are presented. In the experimental part a selection of rocks with a higher expected resistance to high temperatures is made, including detailed information and description. Further in this section we provide the comparison of the properties of individual rocks. Later we describe the most important methods of testing, the procedure of preparation of rock samples and we design an experiment to use for evaluation of resistance of rocks and aggregates under high temperatures.
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Thorium in environment
Adam, Rostislav ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
All known isotopes of thorium are radioactive, 6 of them occur in nature decay chains. Thorium forms mainly cation Th4+ . Because thorium behaves like REE, Ce, Zr, Hf, Sc and U, it is a problem with thorium separation. There is requested leach thorium from ore for production of thorium. Monazite is mostly used for industrial production of Thorium. Electrolysis or chemical reduction are the most spread technologies for metal thorium production. For determination of thorium can be used many methods. Currently there is are usualy used radio-spectrometry or mass-spectrometry for determination of Thorium. Thorium occurs in small amounts in all parts of environment. Most of naturally occuring thorium are in the solid part of environment. Radioactive decay of thorium are using in geochronology. Thorium could be use in future as nuclear reactors fuel. Some other usage of thorium are catalyst in organic synthesis, Welsbach lamps or non-silicate glass. Thorium have also some chemical toxic efects for all organism, but more serious problem is its radioactivity. Final product of radioactive decay is lead. Non-stable products are radium, radon, bismuth, thalium and polonium. All products of radioactive decay have some specific chemical toxicity. 1
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Study of the behavior of selected rocks at high temperatures
Holanec, Aleš ; Sitek,, Libor (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis deals with the observation and diagnostics of transformations that take place in stone slabs of different mineralogical composition during heating to high temperatures. The theoretical part of the thesis deals with a summary of available information about selected types of rocks. Furthermore, it presents findings from the experimental thermal loading of a granite sample. The principles and instruments of laboratory experimental methods that are used to judge the resistance of rocks are described in detail. In the experimental part, the testing methodology is proposed, the procedure of production of rock test specimens is described and the way in which the thermal loading of stone slabs took place is explained. The results of the experiments are shown in the tables and graphs. A comparison of individual tests and properties of selected samples and evaluation of the obtained results is performed.
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Study of utility properties thermal-reflective insulations in the buildings
Holeček, Dominik ; Skříček, Darek (referee) ; Šťastník, Stanislav (advisor)
The diploma thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech Republic. We also get to know with distribution of thermal insulators by material base and use in construction. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermal-reflective insulations. There are mentioned some of the basic characteristics of insulations, material composition and heat transfer mechanism in their structure as well. Practical part describes measurement of thermal resistance of chosen samples of thermal-reflective insulations per measuring device on the principal of Hot Box method. In the next step was determined emissivity of aluminium foils which forms the surface of chosen samples of thermal-reflective insulations. In the end of thesis are defined possibilities of use thermal-reflective insulations in building structures especially in passive and low-energy buildings in climatic conditions of the Czech Republic.
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Anchor silicate expansion material with increased temperature resistance
Müller, Jiří ; Luňáček,, Martin (referee) ; Drochytka, Rostislav (advisor)
This master thesis deals with the development of an expansive anchor material. This material is intended especially for the engineering and power industry where the operating conditions cause thermal stresses of the anchor. In order to meet the requirements for a firm and secure connection of the anchored part, it is necessary to achieve excellent physical-mechanical properties of the developed material such as high compressive strength, high tensile strength based on the base, and resistance to thermal stresses till 200 ° C. All of these processes must be achieved after the ageing of the cement material. Due to the current trend of modern materials that are environmentally friendly, the use of partial replacements for Portland cement is used as a substitute for a primary binder.
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