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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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Desin of new technologies for invert grouting of masonry sewer
Dolák, Martin ; Melichar, Tomáš (referee) ; Drochytka, Rostislav (advisor)
The subject of this work is to find optimal grouting mixture for repairing existing brick sewer with insistence on ecological modesty. Secondary raw and waste materials will be evaluated as a partial replacement of good-quality materials, that are commonly used. Production wastes for which is after necessary adjustment found usage in another sphere of production are named secondary raw materials. In the end will be made a selection of appropriate secondary raw materials for a project of new technology of back grouting identified for repairing currently used brick sewers.
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Modern anorganic foundry binder systems
Kolařík, Martin ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This bachelor thesis deals with newly developed inorganic binder systems. These are mainly developed for their ecological advantages. However, some of the discussed binder systems have better technological properties. Inorganic binder systems are described herein, both on the basis of alkaline silicates and on the basis of inorganic salts. Attention is also paid to bentonite, which is still the most commonly used binder in the world. It turns out that these binder systems will be important for the future of the foundry industry.
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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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Microplastics and their removal from water using sorbents.
Spáčilová, Markéta ; Dytrych, Pavel ; Koštejn, Martin ; Fajgar, Radek ; Šolcová, Olga
The increased occurrence of contaminants in water sources, whether microplastics or other organic contaminants, is currently an ever-increasing environmental problem. This issue is closely related to the mapping of their occurrence in the aquatic environment, as well as to possible ways to eliminate them. The work first characterized the characterization of prepared microplastic particles of the five most commonly used plastics (polyethylene, polyamide, polytetrafluoroethylene, polyethylene glycol terephthalate and polystyrene) using scanning electron microscopy (SEM), Raman spectroscopy and infrared spectroscopy (IR). These microplastic particles were used to prepare simulated microplastic contaminated waters. A methodology for determining the number of microplast particles contained was developed on these water samples. Furthermore, the method of their removal from samples with simulated contamination using functional sorbents was tested. Sorbents based on natural bentonites and zeolites were mainly used. It has been confirmed that the effectiveness of these materials depends not only on their composition and textural properties, but can also be increased by modifying them.\n
Plný tet:  PDF
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The influence of temperature and hydration on the long term stability of the buffer material
Švandová, Jana ; Přikryl, Richard (advisor) ; Galamboš, Michal (referee) ; Havlová, Václava (referee)
The influence of temperature and hydration on the long term stability of the buffer material was studied during two experimental studies - "Mock-Up-CZ" experiment and "Long-term stability of engineering barriers" project. The objectives of these studies is to identify mineralogical, chemical and geochemical changes and describe transformation processes in the bentonite materials due to heating and interaction with various saturation media (with different chemical composition) under controlled laboratory and in situ conditions. The Rokle bentonite suitability for its use in the Czech deep repository of high-level radioactive waste was investigated. Mineralogical changes in the bentonites were evaluated by X-ray diffraction. The material of the barrier of the Mock-Up-CZ experiment is a mixture of nonactivated Rokle bentonite (85 vol.%), quartz sand (10 vol.%) and graphite (5 vol.%). The barrier has been subjected to thermal stress (up to 90 řC) and synthetic granitic water for 45 months. No sample from 70 analysed samples taken at different depth levels and distances from the source of the heat and/or water showed measurable transformation of original smectites. Newly formed gypsum bordered by illite aureole was detected in the upper part of the experimental set-up (backfill samples), i.e. in the...
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