National Repository of Grey Literature 195 records found  beginprevious88 - 97nextend  jump to record: Search took 0.00 seconds. 
Modern Inorganic Building Materials Free of Portland Cement
Sadílek, Jakub ; Opravil, Tomáš (referee) ; Zmrzlý, Martin (advisor)
This bachelor’s thesis is focused on properties of modern construction inorganic ma-terials – geopolymeric concretes. In introductional part of work it is described basic theoretical background, as properties of binders, principles of setting and hardening. For preparation of geopolymer matrix was used secondary or waste materials of energetic and metallurgical industry – fly ashes and slags. In laboratory were prepared four com-positions of geopolymeric concretes combined from geopolymeric matrix with constant compostition and variable composition of aggregates. As aggregates these materials were used: three fractions of quartz sand, steel furnace slag and in one composition also crystals of mineral wollastonit. It was discovered that the use of steel furnace slag as aggregate in geopolymeric concrete has positive influence mainly to compressive strength, but the addition of wollastonite mineral do not evocate expectable increase of mechanical properties of samples.
Side products from power industry as the raw material base for the future
Marko, Michal ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
This work reacts to the worldwide problem related to looking for alternative sources of raw materials. The work deals with analyzing samples of high temperature and fluid fly ashes produced by power plants in the Czech Republic, followed by experimental verification of possibilities to separate some desired components. Based on the elemental and phase compositions, the possibility of aluminum, titanium, and iron extraction to sulfuric acid solution and subsequent selective precipitation using suitable separeation methods was designed and tested in a laboratory scale. Separation of selected elements from the fly ash matrix was carried out at room temperature and then at the boiling point of the used solvent.
Possibilities of the hydrometallurgical process for the recovery of light metals
Skalík, Martin ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis focuses on the assembly of individual stages of the hydrometallurgical process for recovery of lithium, magnesium and aluminum from mica. The main focus was the primary process of hydrometallurgy, i.e. leaching of mica in order to obtain an leachate enriched with lithium, magnesium and aluminum ions. The concentration of metal ions in the leachate was assessed by F-AAS analysis to determine efficiency of the temperature while leaching, leaching time, leaching agent concentration and calcitantion of the input mica.
Self-leveling floors based on secondary raw materials
Darakevová, Michaela ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
The work deals with the use of secondary raw materials in the self-leveling floor systems when used as a secondary raw material perform here especially classic ash, boiler slag and gypsum from flue gas. Work is looking for ways in as much as possible to replace conventional materials used in self-leveling flooring systems, secondary energy products. The aim of this work is to determine the optimal amount and ratio of secondary raw materials in self-leveling flooring compounds so that they are maintained or improved standard properties of these compounds reported in the standards. The work is divided into several points, the first point was first sought appropriate composite binder, where it was used as aggregates reach a standard sand. At other points the sand was then replaced by secondary materials. Were also tested ingredients to influence the rate of cooling, or for the onset of the initial strength.
Possibilities of the hydrometallurgical process for the recovery of light metals
Skalík, Martin ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis focuses on the assembly of individual stages of the hydrometallurgical process for recovery of lithium, magnesium and aluminum from mica. The main focus was the primary process of hydrometallurgy, i.e. leaching of mica in order to obtain an leachate enriched with lithium, magnesium and aluminum ions. The concentration of metal ions in the leachate was assessed by F-AAS analysis to determine efficiency of the temperature while leaching, leaching time, leaching agent concentration and calcitantion of the input mica.
Utilisation of already deposited energy by-products in cement production
Lukášek, David ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis focuses at study of deposited high-temperatured fly ash and its utilization in production of cement. The theoretical part of the bachelor thesis deals with the production and division of cements. The individual advantages and disadvantages of high-temperature and fluid fly ash when added to cements are addressed. The theoretical knowledge was used to design subsequent experiments. The conclusion of the theoretical part of the work deals with pozzolans. The main content of the experimental part was the analysis of raw materials and subsequent analysis of the mechanical properties of the prepared mixtures. The experiments were designed in accordance with valid standards.
Possibilities of using yet unused secondary products from the production of titanium white
Smirnov, Pavel ; Másilko, Jiří (referee) ; Opravil, Tomáš (advisor)
Waste products are an integral part of any production. The production of titanium white is no exception. The bachelor thesis is aimed at finding an application for a secondary product, red chemogypsum which is obtained by neutralizing waste sulfate water. The thesis aimed to find a suitable application for chemogypsum in the construction industry using experiments. The calcium sulfate dihydrate was processed by drying into monohydrate, which is the basic raw material of many products. Furthermore, the composition of the material was determined. Its properties such as onset of solidification, compressive and flexural tensile strength were investigated. Gypsum plasterboards and lightweight and insulating boards were also made. This binder was also used in filling bricks with inorganic insulating material. The knowledge gained from this work can be used to further research and improve products and hopefully make realistic use of this hitherto deposited material in the future. The thesis also provides concrete examples and suggestions for the use of this secondary raw material.
Possibilities of using laser spectroscopy for the analyses of inorganic binders and concrete
Kratochvilová, Lucie ; Hrdlička,, Aleš (referee) ; Opravil, Tomáš (advisor)
This master’s thesis is dealing with the possibility of using laser-induced breakdown spectroscopy for the detection of non-metallic elements (e. g. chlorine) in concrete. These elements cause degradation of concrete which leads to a shortening lifetime of reinforced concrete buildings. In the experimental part of thesis, a methodology for the determination of chlorides in concrete will be created and verified. A comparison of the single pulse and the double pulse configuration of the LIBS will be done on the samples containing only pure chemical substances with known concentrations of chlorine.

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