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Continual helicoidal mixer
Pelka, Tomáš ; Malach, František (referee) ; Malášek, Jiří (advisor)
This diploma project works out and is focused on the continual mixing process of the particular matters. The project is divided into following chapters. Chapter 1 includes mixing theory and information of the experimental work of the particular matters for blade using. In chapter 2 there is Evaluation and calculation of the technical parameters for the mixer. Chapter 3 deals with the engine proposal and chapter 4 includes calculation and design work of the gear transmission. Chapter 5 includes the stress analysis of the shaft and blade with the I-deas software. In attachment there are also the mixer arrangement drawing and detailed drawings of the key parts and groups for the mixer.
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Rehabilitation technology of embankment dams by using suitable types of waste
Michalčíková, Magdaléna ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
The subject of this work is to find an optimal technology for repairing existing embankment dams with emphasis on simplicity and ecological scalability. Next, secondary energy and waste materials will be evaluated as a partial replacement of a quality montmorillonitic clay. The aim of this will be to maximize the use of these waste materials. In the end a selection of materials for the locality will be made. The use of appropriate types of waste for repairs of embankment dams with clay based grouting compound technology has a great potential, especially with those dams that are not fulfilling their function due to their age.
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Mullite Refractory Grog
Zemánek, David ; Tvrdík,, Lukáš (referee) ; Nevřivová, Lenka (advisor)
Refractory aggregate manufactured from common clays, claystones and shales in Czech Republic are mostly classified as fireclay. For specific applications are these grogs not suitable and there is a need to use grogs with higher content of alumina oxide. Theoretical part of this thesis is focused on the mineral mullite, which is one of the basic minerals in Al2O3 - SiO2 system. Research is focused on methods of mullite production, manufacture of recfractory grog and new possibilities in modification of current raw materials. In experimental part is carried out a verification of possible production of grogs with increased alumina content according to the designed composition.
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Foundations in Volume Unstable Soils
Legut, Dana ; Weiglová, Kamila (referee) ; Hauser,, Jaroslav (referee) ; Zdražil, Karel (referee) ; Vašina,, Josef (referee) ; Paseka, Antonín (advisor)
This dissertation is concerned with the foundations in volume unstable soils and objects disorders which are related to this. The thesis was focused on the study of clay and loess soils which are abundant in the geological profile of the Czech Republic. First, the formation of the two groups of soils is introduced, then their properties are examined and finally the influence of vegetation on the former type and the influence of collapsibility in the latter type are investigated. The conclusion is, in fact, a recommendation on the design of structures so that the system of clay / structure is not damaged and that structures are not subject to renovations. Several instance of problems with structures are discussed which were subject to structural repairs employing both a civil and geotechnical engineers.
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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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Diagnostic Methods Suitable for Monitoring of Drying Process of Brick Product
Sarvaš, Ondřej ; Sokolář, Radomír (referee) ; Nevřivová, Lenka (advisor)
This work deals with the study of diagnostic methods suitable for monitoring of the drying process of brick raw materials. Based on the extensive literature search, several parameters are selected, which are appropriate to monitoring during drying. In addition, a methodology for measuring these selected parameters is proposed. In the experimental part, the use of all described methods is gradually verified on the brick raw material with and without shortening additive (also known as grog). Was carried out: measurement of the surface temperature in the climatic chamber, determination of humidity distribution in the sample, determination of moisture diffusivity, determination of tensile strength, determination of ultrasonic wave velocity and determination of dynamic E-modulus of elasticity. Results of experiments and the gained experiences show, that at least two of the above-mentioned monitoring methods are very appropriate and beneficial – determination of moisture diffusivity and determination of tensile strength. In the work was described in detail the procedure of determination of moisture diffusivity of material. The dependence of moisture diffusivity on the moisture content of the dried material, has been described. Also, differences between raw material with grog and without grog has been described. As part of the practical verification of the experiment designed to determine the tensile strength at different humidity levels of test samples. A new shape of the test specimens and a new device were designed to allow them to be attached to a hydraulic press. The results of this work show that the tensile strength of the ceramic green bodies is primarily dependent on the moisture content of the material. The type of raw material almost does not affect the tensile strength.
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Production of refractory aggregate in blast furnaces
Zemánek, David ; Tvrdík,, Lukáš (referee) ; Nevřivová, Lenka (advisor)
Firing of refractory aggregate takes place in blast or rotary furnaces. Raw materials for firing are refractory clays, claystones and shales. Sorting and sieving is performed before firing, in which occurs to formation of the fine clay. This waste is not useful for firing in common way in blast furnaces. Possibility, how to solve this problem, seems to be briquetting of fine clays. This method of proccesing fine clays brings with it new possibilities in refractory aggregate production. By adding a suitable correction material, such as mullite powder, special refractory grog with required properties can be produced on customers wishes.
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Development a new technology of liquefaction and soil stabilization
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
Nowadays, efforts are being made to reduce the environmental impact on the planet even at soils management. Excavated soils are treated as waste and often end up in landfill or depot landfills. It is an effort to exploit these soils. By adding suitable stabilizing additives, features such as yield fluidity, moisture or compressive strength can be adjusted. This composite can be further liquefactioned by using water and suitable liquefiers or plasticizers. Such iquefactioned soils are a suitable self-compacting grouts dressing for excavation for the laying of utility grids, where it is necessary to fill the hole again. The advantage are low economic demands and the absence of excess waste. In the course of this thesis the situation of soil usability in the Czech Republic will be evaluated and possible technologies of soil adjusters will be described. Further, the known types of stabilizing additives and their influence on soil stabilization will be evaluated and verified. Then, different types of liquefying additives will be evaluated and verified. The aim of the thesis is to develop a new technology of liquefaction and soil stabilization.
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Thermo-hydro-mechanical coupling in slope stability: advanced experiments and multiscale modelling
Loche, Marco ; Scaringi, Gianvito (advisor) ; Comegna, Luca (referee) ; Görüm, Tolga (referee)
The complexity of the thermo-hydro-mechanical processes in expansive clays is such that coupled models are needed to explain their behaviour under variable hydraulic, mechanic, and thermal conditions. The effects of temperature changes on the behaviour of bentonite are being studied, in particular, with respect to their role in the chemical and hydraulic insulation of radioactive waste. Results demonstrate that thermal effects can be significant. These effects can also occur owing to different processes, such as seasonal thermal variations in the shallow (possibly clay-rich) soil layers along mountain slopes. Very limited research in this field has shown that some landslides might be activated by thermal excursions. In the proposed project, experiments and modelling at various scales have been performed to better account for thermo-hydro-mechanical coupling and for the control of temperature on the shear strength, and hence on the stability of slopes. An extensive variety of geotechnical parameters are subjected to changes under thermal action. For instance, we need to mention the shear strength. To develop a more complete framework to account for temperature in slope stability analysis, a multi-scale approach has been defined to improve our understanding on how soil behaves under thermal changes....
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The Essence of earthen Architecture in the Czech Republic
Bažík, Lenka ; Pifko,, Henrich (referee) ; Novotný,, Martin (referee) ; Žabičková, Ivana (advisor)
For ten thousand years people have used earthen building material in their homes and in just the last hundred years advanced society has gradually turned away from it due to the development of modern technology. Earth is currently of little use as a building material, but it is gradually increasing with the importance of sustainability. Earth has its place in contemporary modern architecture and this is what this work tries to point out. The research is based on the assumption that each building material gravitates with its properties, composition and also the knowledge of the builder to create a certain space. Different building materials define different spaces, different construction uses and different details. This research defined the network of knowledge with the central themes of the essence of earthen architecture by the method of grounded theory and subsequently applied the theory in the design of a model case. The proposed small structure represents an ideal rendering of the space from a single material on the basis of acquired and known information about this material. It has massive earthen walls, which man created himself and it provides him the shelter. The shelter rises smoothly from the ground, its main source, it has soft round features, which were created by the touch of human hands, and when it expires, it naturally merges with the ground again.
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