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Development of concrete with limited volume changes
Martanová, Jana ; Skopal, Ing Karel (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with volume changes of concrete. Attention is paid to the shrinkage. They describe the different kinds of volume changes in cement concrete, the reason for their creation and the ways in which they can be eliminated. The practical part is focused on monitoring the volume changes of concrete for 28 days using different amount of plasticing additives.
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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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Waterproof concrete structures and regulations for the design and implementation
Křenek, Daniel ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
This thesis covers the issues of design, production, and property testing in regards to waterlight concrete structures. The testing conducted on the properties fit in accordance to the Czech Republic and international regulations. This thesis covers the issues of design, production, and property testing in regards to waterlight concrete structures. The experimental part focused on the design of the concrete mix, which stems from previous knowledge of individual, and speific regulations. Various types of cement were particularly examined along with studying the effects of admixtures that were partially replaced by cement with propoerties of watertight concrete
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Issues of design and testing of waterproof concrete fot tunnel lining
Merta, Michael ; Voves, Jiří (referee) ; Hubáček, Adam (advisor)
The diploma thesis deals with the issue of waterproof concrete and testing its properties. The theoretical part is conceived through research on existing knowledge relating to waterproof concrete. Emphasis is placed on the possibility of using a waterproof concrete for structures, such is e.g. tunnel lining. The experimental part is focused on the laboratory testing of waterproof concrete. Particulary examined was the effect of various admixtures as a partial replacement of cement. Monitored was the development of compressive strength and flexural strength, development of temperature during hydration in the early stages of maturation of concrete, water resistance of concrete, concrete surface resistance to water and chemical de-icing agents, as well as development of shrinkage during concrete maturation.
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Latex Modified Cement Composites
Kunc, Michal ; Rovnaníková, Pavla (referee) ; Kuřitka, Ivo (referee) ; Havlica, Jaromír (advisor)
The subject of dissertation is a study of physic-mechanical properties and development of self-leveling polymer-cement composite of the ternary binder system PC-CAC-CS modified with chemical additives and polymeric substances. The dissertation systematically describes a four-step optimalization of the composite considering its key properties. Experimental part has been focused on monitoring the impact of composite components on selected final properties. Basic physico-mechanical, structural properties and its relations (compressive strength, porosity, flow abilities, setting times) have been analyzed for deeper understanding of the effects of individual composite components. Methods which quantify the existence of the newly formed hydration product – ettringite (XRD, SEM with EDS, calorimetry, dilatometry) has been chosen as additional study methods on selected combinations. A working prototype of self-leveling polymer-cement composite was successfully developed based on systematic process and using of testing procedures and measuring methods.
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Production technology of plastic bracket bearings motor
Svoboda, Vladimír ; Odehnal, Petr (referee) ; Kandus, Bohumil (advisor)
The target of this dissertation is based on the specified shape of plastic part to develop search technology of plastic injection molds, to the technological design process and construction of injection molds, including the necessary calculations. The project includes a search and a practical sections. Based on information from a search section a suitable material was chosen, which became the basis for practical section. The practical section with basic technology calculation is complemented by filling simulation analysis and stress analysis of critical elements. A part of this dissertation is the set of the drawings.
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Production technology of plastic unit base
Vyškovský, Stanislav ; Kebrle, Ondřej (referee) ; Kandus, Bohumil (advisor)
Thermoplastic injection technology is widely used in all sectors of consumer electronics and automotive industry. The biggest advantage of this manufacturing technology is a high degree of automatization and good reproducibility of the manufacturing process. Another advantage is the possibility of recycling of the gating scrap and defective products. The main task of this work is to calculate the necessary parameters for the injection process, which takes place at the designed injection form. Next part is technical design which includes choice of standard parts of injection mold and idividual semi-finished parts for mold. Thesis continues with selecting the type of injection press based on calculated parameters of the injection process. Thesis is finished by technical-economic evaluation.
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Production technology of mobile phone plastic cover
Heralt, Aleš ; Orel, Daniel (referee) ; Kandus, Bohumil (advisor)
The master´s thesis is focused on technology of injection plastics. The specified part is guard cover of mobile phone. The first part of thesis is focused on description of technology with priority on construction of form. The second part of thesis includes calculations of parameters, which are needed for production, along with techno-economic evaluation of selected construction design.
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The development of grouting for additional sealing of embankment dams
Michalčíková, Magdaléna ; Klablena,, Petr (referee) ; Drochytka, Rostislav (advisor)
Seal of sand or gravel by chemical injection is known and used for a long time. Chemical grouting are however expensive and sometimes the use of cement does not lead to desire effects. So it is trying to find new materials and methodologies injection arrangement works. To achieve savings of chemical products are added to a mixture clay and cement. Clay-cement grouting mix are used not only in order that they are better quality, but also because in this way proposed mixtures have a tendency to penetrate better into incoherent sediments that need additional sealant of chemical injection. For further possible reductions of economic terms the mixture is trying to replace the classic clay. As a suitable substitute for classic clay is to a certain extent the use of secondary raw materials. Above all it is fly ash. As a part of my thesis I deal with the appropriateness use of these materials and examining their properties in the mixture. It was found that by using fly ash were improving consistency of the fresh mixture, reducing the amount of water-cement ratio and reduce shrinkage of the mixture. On the other hand, by using fly ash has been increasing decantation, permeability atc. In the next stage of my work was examined the influence of the quality of cement, lime and liquefaction in the mixture. The aim of thesis is to propose the optimal injection mixture for additional sealing earth dams.
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The research of cause of failure of concrete elements Face Block
Eger, Lukáš ; Husařík, Petr (referee) ; Dufka, Amos (advisor)
This master thesis focus on the analysis of effects that cause defects in concrete blocks. Experiences show that the defect of the blocks are often manifested in the form of cracks. Great rate of occurrence of defects is attributed to volume changes of poor quality concrete filler. The aim of this master thesis is to analyze the finding from the practical use and exploration of the requirements for the actual blocks and especially the concrete filler which is used to make monolithic structures built from these blocks. The attention will be paid to the interaction between the block and the concrete filler. Here we focus mainly on the volume changes caused by a change of moisture level and especially the cyclic moisture.
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