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High-performance concretes based on the secondary raw materials
Sáček, Josef ; Brandštetr, Jiří (referee) ; Šoukal, František (advisor)
This work is devoted to study of physical-mechanical properties and structure of high performance concretes (HPC) based on portland cement. The attention is focused on possibility of substitution of economic high-cost components of concrete with utilization of secondary raw materials or cheaper components. Properties of raw materials and their influence on whole quality of concrete were tracked by various methods. Mechanical properties of prepared HPC samples were tested especially (compression and flexural strength) with further microscopic study of structure. Isoperibolic calorimetry and X-ray powder diffraction method were also used for concrete characterisation. These methods allowed to determine the influence of raw materials on prepared HPC and to carry out a certain optimization among price and quality of this material.
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The reaction of ammonium bisulfate
Sedlák, Filip ; Bartoníčková, Eva (referee) ; Opravil, Tomáš (advisor)
This thesis studies reactions of amonium hydrogen sulfate. It studies chemical and physical properties of this not very examined compound. It deals with description of chemical reactions of thist compound. This thesis studies selected chemical reactions and describes its products. Object of this thesis is to find such reaction of ammonium hydrogensulfate that leads to stable product which would not leak ammonia in alkaline environment based on real experiments. Presence of ammonium hydrogen sulfate in solid residues of coal combustion is a result of inauguration denitrification technologies. A great percentage of fly ashes is used today in buildin industry for production of concrete. Fly ash containing ammonium hydrogen sulfate is unusable for this application, that is why searching for new solution to this incurred situation is needed.
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Design of Hydraulic Burner Mouting
Princ, Pavel ; Horňák, Samuel (referee) ; Dvořáček, Jiří (advisor)
This bachelor thesis deals with constructional solution of gas burner clamping and control. The first part is dedicated to the general treatise about artificial aggregate production and its usage. Following parts look into possibilities of guarding the level of charge, which has just under burner high temperatures around 900 - 1000 °C. Proposal of mechanism, which keeps burner in constant height above the level, is done in last part..
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System for Exhausting of Combustion Gases over the Sintering Grate
Kratochvílová, Silvie ; Galas, Radovan (referee) ; Dvořáček, Jiří (advisor)
This bachelor thesis deals with solution for waste gases exhaustion system above the sinter grate. The first part is dedicated to the general treatise about sinter grate, its operations and individual modifications. Another part looks into issues covering placing of the cover above the sinter grate. Proposal of optimal solution of the waste gases exhaustion system is done in last part, where are described reasons, which lead to its choice.
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Possibilities of roman cements preparation by modification of limestone sludges
Petr, Jiří ; Koplík, Jan (referee) ; Opravil, Tomáš (advisor)
It is obvious that binders based on the portland clinker will still play the most important role in the building materials industry. Their high quality, the existence of standards and the affordability are the main reasons. Together with this there is of course an appreciable need for decreasing of energy consumption, carbon dioxide emissions and utilization of secondary raw materials. The roman cement is the possible answer to all of these requests. This historically experienced hydraulic binder, relatively less demanding for the quality of the raw material, is fired by the temperature below the sintering point and even though it does not achieve as good mechanical properties as the portland cement does, in some applications it could be re-established. This would ultimately lead to considerable savings both in the energy and the carbon dioxide emissions.
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Comprehensive flooring system for extreme exposure conditions
Šlancar, Jakub ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
This thesis purposes a solution in form of a high resistance coating reaching a minimum compressive strength of 80 MPa in combination with a adhesive bonding compound and with other additive modifying resulting properties. Furthermore, this thesis is concerned with current state of the floor market and focuses especially on those floors used in extreme conditions, such as heavy manufacturing. Furthermore, The basic testing of this method is also included in this thesis.
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The development of self-compacting concrete with fast runs of strength and elasticity modulus
Skřivánek, Michal ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
My bachelor thesis is about a development of self-compacting concrete. The main advantage of this method is a shorter duration of producing strength concrete and also modulus of elasticity. My analysis consists of describing self-compacting concrete properties, methods for speeding up the process of building strength concrete from less effective heating to using advanced concrete admixtures. Further, an important chapter about influence of concrete mixture composition on modulus of elasticity measurements and in-depth analysis of the SCC mixture composition. Theoretical part is ended by a summary of SCC properties in a fresh or hardened state – all experiment specifics are included. In order to deliver a shorter duration of producing strength concrete and modulus of elasticity in early stages of curing, every SCC mixture mentioned in practical part have been carefully created based on achieved theoretical knowledge with a goal to minimize the impact on rheology of concrete mixture.
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Properties of alkai-activated aluminosilicates subjected to high temperatures
Halasová, Kristýna ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Currently the concept of geopolymer or alkali activated aluminosilicate is very mentioned topic. Many studies concerning utilization of these materials have already been made, but if we want to use these materials in building industry in the future, further research will be needed. This thesis deals with the influence of high temperatures on alkali-activated slag, fly ash and metakaolin-based composites. The work compares mechanical and technological properties, microstructural changes and effect off iller on the geopolymer composites heated at 200–1200 °C. In conclusion, the individual properties are compared and application possibilities of these materials are evaluated.
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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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