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Utilization of waste glass in cement composites
Gottwaldová, Aneta ; Dufka, Amos (referee) ; Bodnárová, Lenka (advisor)
Bachelor thesis deals with the processing of waste glass in cement composites. Bachelor thesis includes a search theoretical and experimental part. Specifically, it was verified by fluorescent waste glass and glass screen at a dose of 5, 10, 15 and 20 weight % of a batch of cement. Properties of composites were examined after 7, 28, 56 and 90 days. We monitored TG analysis and XRD analysis of cement composites with waste glass.
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The issue of the use of carbon nanotubes in cement composites
Pacltová, Klára ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with the analysis of the efficiency of carbon nanoparticles in cement composites. The theoretical part of the bachelor thesis is focused on the research of information about carbon nanotubes and their influence on cement composites. The practical part follows the research of the theoretical part, where is verified the effectiveness of carbon nanotubes in cement composites at different dosages.
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The issue of concrete resistance to high temperatures
Krejčík, Jakub ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Bachelor´s thesis deals with resistance of cement concrete to high temperatures. Theoretical part of bachelor´s thesis describes changes that occures in concrete at thermal loading and behavior of each component of concrete. Next there were discribed ways to improve resistance of concrete to high temperatures, by choosing the right component or by adding fibre reinforcement. In experimental part composites with bassalt and polypropylen fibre and with bassalt aggregates were tested. In these composites changes of compressive strenght and changes of density were mesured according to the thermal loading. Next individual fibre reinforcement polypropylen, celulose and bassalt fibres were exposed to the thermal loading and their changes were observed.
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Mortar with alkali-activated matrix
Černá, Hana ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis addresses the issue of alkali-activated materials and their manufacturing components. In the theoretical part the description of such materials is provided and the requirements for source materials are defined. The theoretical part further addresses the resistance of alkali-activated materials and their lifespan - namely sulphate resistance, chloride resistance, acid resistance, frost resistance, porosity, carbonation, resistance, abrasion resistance and heat resistance. The experimental part of the thesis focuses on compounding four different mixtures of alkali-activated materials. In the loosened stage, the weight was measured. In the hardened stage the weight was measured as well as the tensile strength when bending, the strength under pressure applied, heat resistance, water and defrosting chemicals resistance and formation of cracks.
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Study of properties of Fiber-Reinforced Polymers
Fojtášek, Martin ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Bachelor thesis deals with monitoring the properties of the FRP reinforcement when exposed to aggressive environments that cause degradation. In the theoretical part of this thesis there are described the method of production, the most commonly used types of FRP profiles, the composition of the FRP profiles, durability of FRP profiles against the action of aggressive environment and durability of the FRP material in the damage environment. Further more there are briefly described the most common types of tests on FRP profiles. In the experimental part of this thesis there are defined conditions for laboratory testing of FRP samples, which were stored in an alkaline environment at temperatures of 20 degrees, 40 degrees and 60 degrees. These samples of the FRP were stored and tested after 90 days. Subsequently there are described the changes of the physical properties of rebar in a time when saving in an aggressive environment.
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Elastomer fillers as a potential raw material for concrete and mortar products
Jankech, Filip ; Balog, Oliver (referee) ; Bodnárová, Lenka (advisor)
To attain a sustainable development in the field of building materials, it is necessary to consider environmental, economic, and social aspects of the industrial production. This thesis addresses the first two aspects. Both theoretical and practical research were implemented in order to study the possibility to replace the commonly used RDPs, that are being used in the dry-mix mortar industry as a primary additive, with the industrially processed elastomer waste materials, such as recycled tire rubber. The review of the scientific literature processed within the theoretical research discloses the state of the art in the field of polymer modification of the mortar products and the effect of the commonly used modifiers and elastomer fillers on the performance of mortar and concrete products. The experimental research was implemented to study the possibility of the replacement of the RDPs for the elastomer fillers. The performance of fresh and hardened mortar containing various amounts of elastomer particles was studied. The results indicate, that the partial replacement could be feasible without worsening the performance of the product.
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Study of concrete properties with nanoparticles
Michnová, Kamila ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis discusses the basics of nanotechnology as a science and nanotechnology of concrete. Additionally, it describes carbon nanotubes and the possibilities of their dispersion using high shear mixing and sonication. This thesis further provides findings about ultrasonic dispersion parameters and characteristics of materials with the addition of carbon nanotubes. The experimental of part of this thesis focuses on the possibility of dispersing carbon nanotubes, deals with the issue of incorporating carbon nanotubes into the concrete matrix and describes its effects on the final properties of concrete. It has been observed to which extent the carbon nanotubes may affect selected physico-mechanical properties and durability of concrete.
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FRP composite materials resistance to the effects of selected corrosive environments
Mičkal, Petr ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
This thesis deals with monitoring of the durability of FRP reinforcements in alkaline environments with differing temperature exposures. The theoretical part of the thesis consists of a general description of the FRP composites, the manufacturing of these FRP reinforcements using pultrusion technology, the resistance of these composites in aggressive alkaline environments, and the influence of temperature on the speed and manner of degradation. In the experimental part of this thesis, the FRP reinforcements were placed in an alkaline environment tempered at different temperatures (20 °C, 40 °C, 60 °C). Subsequently, any optical physical changes of the reinforcements were described and evaluated by the use of optical microscopy and the destructive tests of these reinforcements.
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Studying the behavior of high strength concrete at high temperatures
Sovová, Kateřina ; Kirnbauer, tech Johannes (referee) ; Bodnárová, Lenka (advisor)
This master’s thesis is divided into two parts; practical and theoretical. The theoretical part of this study describes the influence of high temperature on concrete structure and chemical, mechanical and physical changes, which take place during the exposure to high temperatures. The thesis also evaluates spalling of concrete and the methods to prevent it, as well as the function of polypropylene and cellulose fibers in the concrete. The practical part deals with design, production and testing of the cement-based concrete with the use of different fibers (polypropylene fibers and cellulose fibers). The properties and the means of applications in high temperatures are also included. The practical part also assesses the influence of high temperature on strength, porosity, visual changes of specimens, changes of surface and degradation of testing specimens due to heat loads according to normative heat curve (ISO 834) and also according to hydrocarbon curve. For clearer arrangement, the experimental tests are divided into two parts and the measured values are evaluated at the end of each part. The conclusion resumes all data obtained by testing and evaluates what is the most suitable formulation. The approach for further research is also discussed.
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