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The properties of contemporary clay bricks
Polláková, Lenka ; Skotal, Zbyněk (referee) ; Sokolář, Radomír (advisor)
Theoretical part of this bachelor´s thesis describes historical overview of progress of brickwork, including their technology, materials for production and products. Another part are requirements for solid burnt bricks, their properties and database of current manufacturers in the Czech republic and Slovakia. The practical part assesse the possibilities of manufacturers and determines the properties of the tested bricks, especially the salinity including frost resistance and appearance.
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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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Fly ash of class C for ceramic technology
Keršnerová, Lucie ; Šveda,, Mikuláš (referee) ; Rovnaníková, Pavla (referee) ; Všianský,, Dalibor (referee) ; Sokolář, Radomír (advisor)
This thesis is focused on the possibilities of the utilization of the fludized fly ash in ceramic technology, especially in the field of brick manufacturing and ceramic tiles. There were used fly ashes from thermal power plants in Hodonín, Ledvice and Tisová. Fluidized fly ash can be used for manufacturing of building materials. There hasn’t been done extensive research in this area. One of the problem is sulphur dioxide leakage during burning. The work describes the behaviour of fluidized ash during firing. The attention is focused on air pollution of sulphur dioxide. The production of SO2 is controlled so that the aim of the work is to find a way how to avoid leaking. It was proved that addition of sodium ions causes the formation of minerals hauyne and nosean during firing. Also is described the behaviour of the fly ash-soil mixtures. The anhydrite decomposition temperature is lower than in pure fly ash. In the end is fluidized ash applied for the production of dry pressed ceramic tiles. This ash can be used in ceramic technology. However, despite the interesting results there are number of problems that need to be solved.
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Development and research of elements of ceramic masonry systems for areas with increased risk of floods
Novák, Vítězslav ; Černý,, Robert (referee) ; Dobiáš,, Jiří (referee) ; Sokolář, Radomír (referee) ; Zach, Jiří (advisor)
One of the most widespread causes of building deterioration is high moisture, which in extreme cases may even arrive as floods. The action of high moisture in a structure often results in damage or alteration of properties, but it can be mitigated with various protective measures, most commonly waterproofing. However, the efficacy of waterproofing depends of flawless implementation. Another effective form of protection against high moisture is the correct choice of location, but the number of suitable construction plots is rapidly decreasing or their price is too high. This is why new construction, particularly family homes, now occurs even in locations known for the increased risk of high moisture. This doctoral thesis focuses on the research and development of the most common masonry systems with structural clay tiles designed to withstand application in flood areas thanks to the special properties of the individual elements, components, and the system as a whole.
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Sintering ability of feldspars and their alternatives
Votava, Petr ; Štubňa,, Igor (referee) ; Sokolář, Radomír (advisor)
The main goal of this Bachelor’s thesis is to compare sintering ability of feldspars which are the most used flux in ceramics with their alternatives such as quarry dust and bone ash. Theoretic part describes process of sintering, sintering activities of used fluxes and their use in the manufacture of ceramics. Practical part is dedicated to description and evaluation of experiment in witch sintering activities of various fluxes ceramic product are compared in dependence on their percent proportion in raw material mix.
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Plasters modified by burnt clays
Soukupová, Eva ; Příhoda,, Jiří (referee) ; Sokolář, Radomír (referee) ; Michoinová,, Dagmar (referee) ; Rovnaníková, Pavla (advisor)
The doctoral thesis deals with the reactivity of burnt clays in connection with modified lime mortars. The theoretical part of the doctoral thesis provides an overview of the properties of lime mortars, their quality and ways of their degradation. The different types of burnt clays (brick powder, bentonites and burnt clay shale), their origin, properties and factors affecting their reactivity and methods of its evaluation are stated. The properties and reactivity of burnt clays are evaluated on the basis of determination of pozzolanic activity, mineralogical and chemical composition, surface area, density, content of the amorphous phase and granulometry in the experimental part of the doctoral thesis. The compositions of lime mortars containing burnt clays and evaluation of an impact of burnt clay on the properties of mortars in the fresh and hardened state are given. Consistency, bulk density, workability and air content of mortars in the fresh state are evaluated. Strength characteristics depending on the time, water absorbability, porosity, capillary attraction, adhesion, coefficient of diffusion resistance, frost resistance, shrinkage, mineralogical composition and microstructure of mortars in the hardened state are evaluated. Attention is also paid to the influence of the cellulose ether addition into the modified lime mortars.
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Characterization of brick clays for the production of THERM bricks
Svobodová, Markéta ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
The Bachelor´s thesis is focused on the comparison of brick claysthat arecalcium and non-calcium and then it determines which of these brick clays are suitable for production of thin wall thermal insulating fittings called THERM. The main influence has CaO contained in the calcium brick clay in the form of calcite. In the theoretical part you can find an overview of the brick clays in the Czech Republic and abroad then requirements for clays and laboratory testing of bricks. In the practical part of the work were performed tests on samples of brick clays used in the Czech Republic. Mineralogical composition differenceis obviousafter firing the brick clays.This difference is caused by occurrence of anorthite calcium brick clay which then reflects in the usefulproperty of brick shard. Based on these tests I make evaluationof the most suitable type of brick clay for processing the THERM fittings.
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Bigots Curve for the Determination of Plastic Body Properties
Suk, Vojtěch ; Nevřivová, Lenka (referee) ; Sokolář, Radomír (advisor)
This bachelor thesis is focused on the use of the Bigot curve as a tool for assessing the performance of plastic ceramic materials. The theoretical thesis is a form of research of available literature. It elaborates a general view on the Bigot curve and possible application properties which derive from it for some specific soil. In the experimental part were determined properties of plastic ceramic material from location Jirčany from which were formed samples made of plastic dough with different moisture content, with the addition of grog and additives. Properties such as shape of Bigot curve, critical moisture value, size of drying shrinkage and drying sensitivity of the soil were monitored on the samples.
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Methylene Blue Test for Plasticity Determination of Brick Clays
Jiroušek, Štěpán ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
The Bachelor thesis is focused on methods for assesing the plasticity of ceramic raw materials (clays). The theoretical part describes the origin, species, chemical and mineralogical composition of these raw materials. Then we describe the preparations and standardized and nonstandardized methods of assesing the plasticity of clay used in the Czech Republic and abroad. The practical part describes executed tests of brick soils specimen used in the Czech Republic. The outcome of this work is to find correlations between these tests and the determined value of sorption of methylen blue.
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