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Resistance to freezing and thawing of hydraulically bound mixtures to roads
Švantner, Lukáš ; Mondschein,, Petr (referee) ; Stehlík, Dušan (advisor)
The theoretical part of this master’s thesis contain comparing the methods of endurance hydraulic bound mixtures of concrete recycles against influence of water and freeze in Czech republic and some other states of The European Union. The practical part is dedicated about laboratory testing concrete recycles with mixtures of binders and its endurance against the water and freeze cycles in Czech republic. In made rollers is compared the strength in pure compression with the strength in pure compression after freezing cycles. From the results of the exams is considered about suitability of using these hydraulic bound mixtures to road construction depending on the kind of use binder, amount of the binder and water. Results of this thesis will be used to revision of national postscript of technological norm ČSN 73 6124-1.
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Utilization possibilities of industry gypsum and secondary materials containing for preparation of composites
Weiglová, Jana ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
The work studies the possibilities of the utilization of secondary raw materials produced by power industry. It addresses mainly the gypsum by-products and fluidized coal combustion ash. As for the secondary raw materials the content of sulphites is observed and the dependences of their transformation to sulphides via natural oxidation by air oxygen or by addition of adequate oxidant are studied. The work follows with describing the effect of sulphides contained in raw materials on the mechanical properties of composites prepared from several various matrices such as alumina or portland cement, lime or portland clinker. As for pure portland clinker the ability to retard the setting is also observed. The amount of contained sulphites is measured volumetrically via indirect titration of iodine surplus by sodium thiosulphate with the starch size as the indicator.
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Development of ceramic shell for manufacturing of large Al investment castings
Hýbal, Ondřej ; Šmatelka, Jakub (referee) ; Horáček, Milan (advisor)
This diploma thesis deals with the choice of the most suitable composition of a ceramic shell mold for aluminum castings made by investment casting technology. The most suitable composition of the ceramic shells is chosen based on the results of the tests and from economic point of view. This thesis also deals with evaluation of the current conditions of the production of ceramic shells in Alucast, s.r.o and recommendations for stabilizing the process of manufacturing ceramic shell molds.
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New possibilities of using secondary raw materials for the renewal of the railway substructure
Buřičová, Karolína ; Luňáček,, Martin (referee) ; Drochytka, Rostislav (advisor)
The work is devoted to new possibilities for the recovery of secondary raw materials and track bed waste with a combination of both suitable and unsuitable soils. The aim of the thesis is to develop a new functional sample suitable for the recovery of a substructure of railways based on secondary raw materials. The theoretical part addresses the issue of the use of soil and secondary raw materials as the base layers of railway structures, and is focused on the possibilities of soil adjustments or enhancement. The practical part is focused on the analysis and selection of potentially suitable raw materials, the design of new raw material mixtures containing concrete recyclables, waste from cleaning the auto mixer and waste from cleaning the rail bed. Further, to modify the mixtures designed with fluid ash from biomass combustion to achieve higher toughness. Then they will be experimentally verified and based on the results the optimal formula for use in the solid of the railway bottom will be determined. Final optimal recipe achieving basic required parameters for use in active zone without the requirement for frost resistance and ecology is composed of 30 % of F4-CS, 4 % of portland cement CEM II-B/LL, 3 % of lime hydrate, 70 % of recycled concrete and 10 % of fluid ash from biomass combustion.
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Development of a thermal insulating material designed for use with high temperature
Dokoupil, Martin ; Frajt, Daniel (referee) ; Drochytka, Rostislav (advisor)
The work deals with the development of a new thermal insulation material that contains a secondary raw materials or waste. It is an insulating material with the requirement of resistance to high temperatures - 200 ° C and 500 ° C. Type of material is determined by the way of reducing density - direct and indirect. Direct is achieved by adding lightweight aggregates, indirect is achieved by gas evolution through chemical reaction and the subsequent incorporation of gas into the structure of the material. This thesis is part of the MPO TIP č. FR-TI 2/340 project.
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Electrode Materials for Li-S Batteries
Jaššo, Kamil ; Almáši,, Miroslav (referee) ; Syrový,, Tomáš (referee) ; Kazda, Tomáš (advisor)
This thesis is focused on the research of electrode materials for lithium-sulphur (Li-S) batteries, with an emphasis on the optimization of the process of preparation of positive electrodes through the modification of the individual technical steps of the manufacturing process and the selection of a suitable binder. The theoretical part of the thesis is devoted to terminology and battery issues with emphasis on Li-S batteries, their working principle, shortcomings, critical parameters for commercialization and existing research in this field. The practical part of the thesis deals with the influence of the compression pressure used in the production of positive electrodes on the electrochemical properties of the resulting Li-S cells. In the next part of the thesis, the influence of the binder used on the resulting electrochemical properties is investigated. In the following sections, the influence of the thickness of the electrode material layer and the ratio of its individual components (C/S) on the resulting electrochemical properties of the Li-S cell is analyzed. On the basis of the measured results, the optimum conditions for the preparation of the positive electrodes of the Li-S cells have been identified with respect to the individual technical steps of the manufacturing process.
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Thermal aging of nanocomposites
Janíček, Martin ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
This thesis deals with issues of properties of nanocomposites and it´s heat aging. In the first part there are theoretically analysed some of the basic therms connected with nanocomposites. Also there are outlined basic methods of production of these matherials. The most important is specification of individual properties when bigger attention is gived to electrical properties. Practic part deals with heat aging of samples of nanocomposites filled with nanoparticles Al2O3. There was monitored impact of time of aging on values of internal resistance, dissipation factor and relative permitivity.
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Stabilization of the base layers of roads by using secondary raw materials
Buřičová, Karolína ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
The bachelor's thesis deals with the up-to-date subject of secondary raw material usage. The aim of this thesis is to suggest a potential way of these materials’ usage by stabilization of base courses of road or railway constructions. Parameters of individual primary and secondary commodities are evaluated and the acquired knowledge in the field of stabilization is presented. An optimal technology for stabilization is suggested and applicability of used materials and their subsequently prepared mixtures is experimentally verified in the experimental work of this thesis.
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Development of adhesive material for installation of cast basalt elements on metal base
Šikral, Martin ; Hodná, Jana (referee) ; Drochytka, Rostislav (advisor)
The diploma thesis deals with the development of polymeric adhesive material for the installation of cast basalt elements on a metal surface. The aim of this work is a development of the new adhesive material for the fixing of cast basalt elements to a metal base in high chemical stress environment and at higher temperature conditions. Furthermore, the thesis explores the possibility of using secondary raw materials as a substituttion of primary materials in the form of fillers. The thesis is also focuses on the determination of the advanced testing methods to verify the properties of devoloped adhesive materials, including monitoring the microstructure of the contact zone between the adhesive material and the surface.
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