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Study of the influence of additions on the durability of aerated concrete
Halešová, Adéla ; Voves, Jiří (referee) ; Hubáček, Adam (advisor)
The aim of this work is to summarise and consider the possibilities of using admixtures and their influence on the durability of aerated concrete.This bachelor's thesis is based on research findings concerning aerated concrete. Furthermore, it deals with the study of inert and active additions. The experimental part is focused on testing trial samples with the addition of admixtures. It examines what is the rate of the possible chosen physically-mechanical features such as the rate of air density, the durability of surface against the effect of water and chemical defrosting substances and achieving the required strength.
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Possibities to increase the frost resistance of brick body
Keršner, Štěpán ; Šveda,, Mikuláš (referee) ; Sokolář, Radomír (advisor)
This thesis, which comprises of a theoretical and a practical part, deals with possible means of increasing ceramic body frost resistance. The current state of research in the field of ceramic body frost resistance is summarized in the theoretical part. The practical part is divided into two sections. In the first section, the influence of firing temperature (820 °C and 1020 °C) and duration (2, 4 and 6 hours) on frost resistance and several other parameters is assessed by means of experiment, using a specimen of brick body made of mixes currently used in roof tile production by TONDACH Šlapanice and TONDACH Dolní Jirčany factories. In the second section of the practical part, two modifications are introduced of the mixture currently used in roof tile production in the TONDACH Šlapanice factory – GE clay and zeolite supplements were added, the effects of which are verified by means of experiment using specimens fired in a kiln designated for ceramic masonry blocks and alternatively in a kiln used for firing TONDACH Šlapanice roof tiles.
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Study of microstructure of autoclaved aerated concrete with using of secondary raw materials
Martanová, Jana ; Suchý, Peter (referee) ; Kulísek, Karel (advisor)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.
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Proposal for a new method of purification of polyether polyols by zeolits.
Hedvigy, Marek ; Čamaj,, Vladimír (referee) ; Krištín, Michal (advisor)
This diploma thesis covers the tracking of final quality parameters of polyether polyol – Slovaprop G-160, which are: amount of sodium and potassium, color, acidity and amount of water. The most important parameter was the amount of sodium and potassium, because the aim this thesis was to achieve satisfactory amount of sodium and potassium after the purification process with use of zeolite (ZeoCem Micro 200) and to improve the effectivity of the purification and filtration process in the production of polyether polyol – Slovaprop G-160. In theoretical part, Diploma thesis deals with the method of production and characteristics of polyether polyols for the production of polyurethane foams. Practical part consists of nine series of experiments in order to get addictions of amount of sodium and potassium to temperature, weight of Pyrofos and amount of zeolite. Based on laboratory test a new way of purification process of polyether polyols was developed. With this new purification process the production time of Slovaprop G-160 will be shorten thanks to removal of hydrolysis from the reaction process and in the end of the process the time needed for drainage is reduced in half.
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Properties of Zeolites and Their Use in Building Binders
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
Zeolites, such as natural or synthetic aluminosilicates, have a wide range of applications. Their application in the construction industry tends to use zeolites as impurity type II. However, it has to prove their reactivity and affect the content of calcium hydroxide in the concrete. The aim is to determine the effect of zeolite as a partial replacement of cement in different concentrations on the mechanical properties of fine-grained concrete and consumption of calcium hydroxide.
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Immobilization of heavy metals in the cement matrix with the admixture of natural zeolite
Semerádová, Nikol ; Bayer, Patrik (referee) ; Vyšvařil, Martin (advisor)
Heavy metals released to the natural ecosystem constitute significant risks not only for organisms, but also for water supplies in the nature. There are a number of analytical methods for the determination of heavy metals. Each of them is suitable for different element and its character. Since the results of the analysis are applied during the solidification and stabilization, it is necessary to ensure the highest correlation between hazardous waste and solidification medium for maximum inhibition of toxic ions. This work investigates the stabilization of heavy metals binders based on cement base with admixture of the natural zeolite and its possible use for the solidification of heavy metals in soluble form.
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Cleaning effect of unconventional filtration materials
Fialová, Tereza ; Hynánková,, Eva (referee) ; Kriška-Dunajský, Michal (advisor)
Constructed wetlands and the soil filters are water treatment devices using the filter material that in most cases consists of natural river gravel, coarse sand or crushed stone. Master´s thesis deals with the research of cleaning effect of unconventional filtration materials, or more precisely with examination to load real waste water in a filtration column, to prove their ability to be used as an alternative medium that can ensure better cleaning effect. For the research work following metallurgical industry materials were used: fine slag and coarse slag 8-16 mm, materials from the natural character: zeolite, keramzit, a plastic material: PUR-foam. Also the traditional materials of fine gravel and coarse gravel were tested to compare the cleaning efficiency. Both the hydraulic and the cleaning efficiency of all above mentioned materials were tested. The examined hydraulic parameters are particularly porosity, hydraulic conductivity and suspended solids, turbidity and oxidation-reduction potential of both the inflow and outflow of the filter columns were determined. Accredited laboratory set the inflow and outflow of the filter columns BOD5, CODCr, total phosphorus, total nitrogen, nitrite, nitrate, ammonia and dissolved oxygen. By evaluating the results of the measurements it is determined which materials are suitable to be applied in the constructed wetlands and the soil filters. This filtration column was modeled by program HYDRUS and the result was compared with real results.
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Possibilities of using different types of admixtures in shotcrete technology
Berčík, Martin ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
The Bachelor’s thesis is conceived in the form of research findings on current knowledge of inert and active ingredients and their effects on the shotcrete. It focuses mainly on the composition of individual ingredients, their function executing in the concrete mix and explains how they affect the selected physical and mechanical properties. The work enlightes the importance of using co-products from the industry production as an additive to concrete in terms of both ecological and partly economical.
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Preparation of soil conditioners and characterization of their nutrient release kinetics
Horváthová, Lenka ; Jančář, Josef (referee) ; Lepcio, Petr (advisor)
This diploma thesis deals with the preparation of multifunctional soil conditioners based on potato starch, in order to slow down the release of nutrients. Materials with different contents of superabsorbent polymer and zeolite were prepared. Spectra indicating the formation of new bonds were evaluated by infrared spectroscopy. The kinetics of nutrient release were observed in the prepared samples of soil conditioners in an aqueous medium, where nutrient retention was demonstrated. Other samples were tested on plants, which proved a mostly positive effect on growth and other factors.
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