|
| |
|
|
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
|
|
|
The development of composite material system with focus on matrix for extreme conditions
Gratclová, Kamila ; Gross,, Tomáš (referee) ; Bydžovský, Jiří (advisor)
The thesis deals with composite systems, with a focus on matrix resistant to extreme conditions. The aim of this work was to research and development matrix, resistant to high temperatures, typical in case of fire. Used theoretical knowledge were realized with subsequent laboratory research. Attention was paid matrices based binder mixed with any alkali activation of alternative raw materials and geopolymers. Scattered reinforcement featured polypropylene fibers. The subject of the practical part of the two alternatives, including a matrix based on basic ingredients - cement, alternative raw materials - high fly ash, blast furnace slag, geopolymer and polymeric components incl. combinations thereof. Laboratory research conducted by determining the fundamental material properties such as density, strengths, etc., after heat exposure. The developed materials were subjected to a temperature 1400 ° C. The conclusion was selected several recipes that were based on the resulting values found to be optimal.
|
|
|
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.
|
|
|
The development of fire-resistant repair mortars with fine-grained filler
Záruba, Jiří ; Gross,, Tomáš (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis is focused on fire-resistant repair mortar with fine-grained filler. The aim of this work is the research and development of fine-grained Mortars resistant to high temperatures, which are characteristic at the beginning of the fire. The theoretical knowledge with subsequently realized laboratory verification was used. At-tention was paid to the masses based on the mixed binder comprising cement and blast furnace slag, respectively. high-temperature ash. Cellulose fibres were used as the dis-persed reinforcement. Two kinds of aggregate were assessed - fly ash agloporit and am-phibolite incl. combinations thereof. Laboratory tests were carried out via determination of basic material properties (density, strength, consistency, dimensional changes etc.) after exposure to extreme temperatures. A substantial part of the research was also study of different cooling conditions - slow and fast (water and air). Selected formulations were subjected to temperatures up to 1200 ° C. In the conclusion is selected several recipes that have been found to be optimal for continuing research on the basis of the results and findings.
|
|
| |
|
|
Change in the durability of concrete made of recycled concrete by alternative addition of ceramic admixtures
Stavař, Tomáš ; Hoffmann, Oldřich (referee) ; Stehlík, Michal (advisor)
The master thesis dealing with problematic about durability of concrete, with use of recycled concrete and addition of silica additions. Predominant for resistance of concrete constructions is surface layer, through which aggressive gasses and liquids penetrate from surrounding environment. The most important indicator of concrete durability is ability of surface layer transmissions of aggressive substants. In experimental part will be defined the actual state of surface layer by normal testing methods. The transmissions of surface layer will be tested on concrete cubes. Tests for transmissions of air (method TORRENT), of water (method ISAT), of acid gases (dept of carbonation by quick test in 98% CO2) will be carried out and also strength tests. Assessment of positive or negative influence of additions and amount of cement on durability and mechanical properties of concrete will be discussed in conclusion.
|
|
| |
|
|
Study of influence of admixtures on electrochemical characteristics electrode materials for lithium-ion batteries
Nejedlý, Libor ; Jirák, Tibor (referee) ; Sedlaříková, Marie (advisor)
The bachelor project deals with new intercalation materials with admixtures for positive electrode of lithium-ion accumulators. Concretely, the project works with new preparation methods of electrode materials and compares them with long-established industrial process. For this purpose were used electrochemical measurements and structure analysis obtaining materials. The theoretical part of the project is devoted summary of electrochemical power sources, electrochemical reactions, recycling and future of Li-ion batteries. The practical part describes electrochemical methods, measurements and discusses achieved results.
|
|
| |
guest ::
