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Cement worm conveyor
Weingärtner, Jan ; Malášek, Jiří (referee) ; Škopán, Miroslav (advisor)
This bechelor‘s thesis deal with constructional analysis of the worm conveyor. I describe here design calculation of main parts of conveyer, design of propulsive system, solidity control of functional parts, problem of heat dilatation while higher temperatures transported materials and way of mode imposition shaft.
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Specification of the phase composition of Portland clinker
Vávrová, Alžběta ; Dlabajová, Lucie (referee) ; Másilko, Jiří (advisor)
This bachelor thesis deals with the determination of the phase composition of portland clinker and its optimization. The X-ray fluorescence spectroscopy, X-ray diffraction analysis and optical microscopy were used to solve this task. In the experimental section, X-ray fluorescence spectrometry results were used to calculate the potential phase composition of the clinker using the Bogue method. Then the X-ray diffraction analysis followed, it was used not only to determine the phase composition but also to determine amorphous content in the clinker. The microscope integration method was used to study the samples using optical microscopy. The obtained results were compared with each other and the main deficiencies of the individual methods were identified.
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Study of the dependence of concrete composition on the values of elasticity modules
Křížová, Klára ; Kolář,, Karel (referee) ; Adámek, Jiří (referee) ; Ďurica,, Tibor (referee) ; Hela, Rudolf (advisor)
The modulus of elasticity is one of the basic characteristics of concrete defining elastic deformation of concrete and it plays a significant role in the static design of structures. Due to current trends in concrete technology, offering a wide variability in the proposals of the composition of concrete, there are changes not only in strength characteristics but also in the modulus of elasticity of concrete. The aim of this doctoral thesis is to study the dependence of different compositions on modulus of elasticity of concrete. Design of concrete composition is prepared with respect to the use of different types of cement, mineral admixtures, types and fractions of aggregates. The work is mainly focused on the determination of static modulus of elasticity in compression with the addition of dynamic modules. In the first phase determined modulus of elasticity are compared with tabulated values according to Eurocode 2, which are derived for the specific strength class of concrete. Part of this work is the compilation of the main technological aspects of concrete which can favorably affect the modulus of elasticity.
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Development of chemically resistant sprayed mixture
Hermann, Radek ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
Production wastes for which a direct use in another production is found become secondary raw materials. There are several institutions in Czech Republic and in the world, which are currently dealing with the issue. This thesis deals with the issue of cementitious spray concrete mixtures and deals with the possibilities of using secondary raw materials and waste from production as partial replacement of binder and filler in these mixtures. The aim of this theses is to optimize the composition of additives in the recipe of the commercially produced pray mixture and to verify the influence of the degree of substitution of binder or filler by secondary raw materials on its physical-mechanical properties. The aim is to maintain or increase these properties while substituting the binder and filler as much as possible. After the evaluation of results, it is possible to say, by suitable optimization of the additives it is possible to achieve a significant improvement of the physical-mechanical properties of the mass and furthermore, from the results of this thesis follows, that by substitution of 100% fine filler in combination with substitution of 30% binder it is possible to maintain or increase the physical-mechanical properties after 28 days of curing and to significantly increase these properties after 90 days of curing. The results of this thesis are also related to the reduction of economic impact on production of the spray mixture, mainly due to the use of secondary raw materials.
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Cold recycling of flexible pavements
Řehulka, Martin ; Koudelka, Tomáš (referee) ; Varaus, Michal (advisor)
The bachelor´s thesis is focused on recycling of the flexible pavements in general, namely cold recycling. This modern technology was introduced in the Czech Republic after 1989. The first half of the thesis describes theoretically various types of recycling of flexible pavements, where the greatest attention is paid to this technology. The second part describes the section of the modernization D1 motorway where this cold recycling was applied. The technological process, including visual documentation and control tests, is documented.
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Cold recycling
Šperka, Pavel ; Stehlík, Dušan (referee) ; Hýzl, Petr (advisor)
Bachelor’s thesis focuses on the processing of knowledge of flexible pavements cold recycling, especially on the technologies if full depth reclamation and partial cold recycling in-place and the benefits or reasons for the increased use in the Czech Republic. In the practical part of the thesis the current status of selected sections, which were made by practical cold in-place recycling technology, is evaluated. In the end of the work the success of this technology is evaluated.
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The effect of particles size on the properties of mortars.
Sehnal, Tomáš ; Krátký, Josef (referee) ; Šiler, Pavel (advisor)
The consumption of concrete as a building material is still increasing over the world. Concrete production is closely associated with CO2 and other greenhouse gases emissions. The reduction of these emissions can be achieved by a higher utilization of secondary raw materials in cement mixtures. This bachelor work is focused on the using of secondary raw material, finely ground granulated blast furnace slag and fly ash from fluidized bed combustion and high temperature combustion. The properties of milling pure cement and cement mortars with addition of secondary raw material will be measured. Compressive strength, flexural strength, and calorimetric measurement will be performed for these prepared mortars.
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Methods for Monitoring of Volume Changes of Cement and Polymer-modified Mortars
Vrablová, Simona ; Sedlmajer, Martin (referee) ; Žižková, Nikol (advisor)
Bachelor thesis is focused on monitoring of volume changes in polymer-modified mortars. Using Czech and foreign literature searches are processed, in which mortars in general and ongoing chemical and physical processes are described. Thesis is further concerned with description of polymer-modified mortars and with explanation of polymer-matrix forming mechanisms. The following are noticed volume changes and experimental methods of their investigation. Experiment is performed by monitoring the volume changes in polymer-modified mortars using two selected methods. For comparison volume changes in gypsum are also measured.
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Possibility to use technology of rammed earth for building a family house
Zadražil, Lukáš ; Přikryl, Michal (referee) ; Žižková, Nikol (advisor)
This Diploma thesis deals with possibilities of utilizing earth as a building material for con-struction of detached houses using the rammed earth technology. Research in domestic and foreign literature led to description of the historical development of building from earth, overview of historical technologies and historical development of the technology of rammed earth. Subsequently, the thesis deals with nowadays very relevant problematics of sustainable construction, which is closely related to the use of natural materials, such as earth. Furthermore, the thesis describes the technology of rammed earth with examples of already realized buildings, both in the Czech Republic and other countries. The last part of the research describes selected methods of testing the physical-mechanical properties of rammed earth used abroad. The first section of experimental part deals with the design of earth mixtures for three specific sites (Dolany, Valchov and Dolní Těrlicko), using a computer model in Excel. The rest of experimental part contains the design of methodology for the production of test specimens for the pressure testing, and selected tests are performed for better knowledge of the physical-mechanical properties of the designed earth mixtures. The last part of the thesis discusses the problematics of legislative process of permitting rammed earth buildings and practical construction recommendations.
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