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Possibilities of using different types of admixtures in shotcrete technology
Berčík, Martin ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
The Bachelor’s thesis is conceived in the form of research findings on current knowledge of inert and active ingredients and their effects on the shotcrete. It focuses mainly on the composition of individual ingredients, their function executing in the concrete mix and explains how they affect the selected physical and mechanical properties. The work enlightes the importance of using co-products from the industry production as an additive to concrete in terms of both ecological and partly economical.
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Research on the Preparation of Masonry Mortars
Koláček, Tomáš ; Dvořák, Karel (referee) ; Gazdič, Dominik (advisor)
This thesis deals with development in the preparation of masonry mortars. The theoretical part focuses on basic knowledge of mortars, individual types of mortar, preparation methods and individual components from which the mortar is composed. The practical part deals with the proposed reference and modified mortar mixtures and compares their technological properties.
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Effect of admixtures on the properties of metakaolin geopolymer
Halasová, Kristýna ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Geopolymers are amorphous to semi-crystalline aluminosilicate polymers which are formed from inorganic polycondensation reaction of a solid aluminosilicate precursor with an alkaline sodium hydroxide or silicate. The resulting materials exhibit high durability, resistance to aggressive environments, high temperature resistance and many other properties that make them have received much attention in recent years, not only in construction. This thesis describes the influence of additives commonly used in concrete and mortar (water reducing, superplasticizer, air-entraining, foamer and defoamer, anti-shrinkage, stabilization) on the behavior of metakaolin in geopolymer fresh and hardened state. It describes metakaolin geopolymer effect on rheological properties of fresh mixtures, compressive strength and flexural strength after 28 days and a density in the fresh and hardened state.
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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.
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Electrodes for lithium-ions batteries based on LiCoO2
Nejedlý, Libor ; Čech, Ondřej (referee) ; Sedlaříková, Marie (advisor)
This master´s thesis deals with electrodes for lithium-ions batteries based on LiCoO2. The first part of the project is devoted to the characteristics of Li-ion batteries, electrochemical reactions and characteristics of electrode materials. The next part describes an experiment that deals with the effects of NA doping on performance of layered materials for lithium secondary batteries. The materials were measured by cyclic voltammetry, impedance spectroscopy and galvanostatic cycling.
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Study of the effect of selected types of aditives on the properties of cement composites
Kavka, Lukáš ; Ťažký, Tomáš (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis describes admixtures for concrete. It deals with the influence of admixtures on the properties of cement composites in the fresh and hardened state. The theoretical part described the individual components of concrete, where the main attention was focused to inert admixtures and their effect on mechanical properties, shrinkage, resistance of cement composites to aggressive medium. Furthermore, the effect of admixtures on concretes with recycled aggregates was described. In the first stage of the practical part, cement mortars with 25, 35 and 50% replacement of cement admixtures were created. In the second stage, concretes with admixtures and a minimum strength class of C30/37 and C50/60 were created. Finely ground granulated slag, micronized limestone and granite stone dust were used as admixtures in mortars and concretes. The change of properties in the fresh and hardened state was observed on cement composites.
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Research on the Preparation of Masonry Mortars
Koláček, Tomáš ; Dvořák, Karel (referee) ; Gazdič, Dominik (advisor)
This thesis deals with development in the preparation of masonry mortars. The theoretical part focuses on basic knowledge of mortars, individual types of mortar, preparation methods and individual components from which the mortar is composed. The practical part deals with the proposed reference and modified mortar mixtures and compares their technological properties.
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Reactive Powder Concrete
Gabko, Miroslav ; Klečka,, Tomáš (referee) ; Hela, Rudolf (advisor)
Reactive powder composites (RPC) have been recently a subject of many researches of modern concrete technology. This type of concrete is very fine and its behaviour exceeds the other types of concrete, therefore there are new possibilities of its use. The design and production of RPC is complex technology process which needs to gain new results in RPC research to get the best features regarding its higher price. This thesis is focused on design of reactive powder concrete (RPC200), which compressive strength is between 200 – 300 MPa. Next goal is to prove the influence of curing regimes like high temperature or pressure, and also check the possibilities of production of low cement reactive powder composite (LCRPC).
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