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Composite materials with silica matrix in the environment of high temperatures
Lisztwanová, Ewa ; Luňáček,, Martin (referee) ; Bydžovský, Jiří (advisor)
This thesis deals with the study and design of composite materials based on silica matrix suitable for extreme conditions, eg. for the repair of concrete structures with anticipated increased risk of fire. The theoretical part summarizes basic knowledge concerning the fire resistance of structures and the behavior of the composite system during extreme conditions. Theoretically oriented section also contains information on alkali-activated materials and their use in high temperature environments. Based on the evaluation of the theoretical part of the experiment were designed and tested different types of composite materials with increased content of raw materials from alternative sources. Laboratory research has been based on testing of basic physico-mechanical parameters including phase composition and microstructure of the proposed formulations before and after thermal exposure of 1200 ° C. Also considered was the effect of different cooling conditions.
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Cement-bonded particleboards with utilization of alternative raw materials
Urbánek, Libor ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis is focused on effective utilization of currently produced alternative raw materials in the production of cement-bonded boards. The emphasis is primarily on the scraps and dust arising from the processing of cement-bonded slabs, as well as on slag and limestone. The theoretical part contains a survey of current knowledge about the given issue. In the experimental part, the alternative raw materials were analyzed in detail and their influence (as modifier components of the matrix and the filler) on the properties of cement-bonded slabs was examined. Research and development took place using physico-mechanical, thermal and microstructural methods.
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Development of new types of composites for concrete rehabilitation with increased protection reinforcement
Taranza, Luboš ; Durica,, Tibor (referee) ; Dohnálek,, Pavel (referee) ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
Around the world there is a great number of reinforced concrete structures, who´s life cycle, for which they were designed, is significantly shortened due to action of various aggressive environments, or due to defects created during the construction process. (i.e. insufficient steel reinforcement cover depth). One of the most common causes of problems in reinforced concrete structures is corrosion of steel reinforcement. It is necessary to repair structures degraded in this fashion and return them to their original state. We made a unique polymercement concrete repair system was developed with value added. Corrosion inhibitors, including the newly developed, are implemented into its polymercement matrix, which significantly limit the corrosive processes in all new materials. The principle of proposed solution is application of repair system on a corrosion damaged structure, and then the active substances in the repair material will penetrate into substrate concrete and protect corroded steel reinforcement. Another value added is the application of recycled raw materials into the proposed materials, which has indisputable environmental effect and simultaneously allows for improvement of some properties of the repair materials. Further was developed a new method for detecting corrosion inhibitors in concrete.
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Optimisation of cement-bonded particleboard matrix composition by using alternative raw material sources
Roháček, Lukáš ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis deals with possibility of utilization raw materials from alternative sources for production of cement-bonded particleboards. In theoretical part the possibilities of modifying composition of cement-bonded slabs with emphasis on their matrix are discussed in detail. On basis of the findings and their evaluation, waste from the formatting of cement-bonded particleboards, micronized limestone, heat sink and high temperature fly ash were selected to the composition modification. The mentioned raw materials were analyzed and subsequently tested as substitutes for the matrix of cement-bonded particleboards in the experimental part. The properties of the proposed materials were tested even in the longer term, including the microstructure.
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Study of influence of secondary raw materials on mechanical resistence of the industrial floors
Figala, Petr ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
Secondary raw materials are nowadays increasingly used as materials in many sectors of the construction industry. This thesis evaluates current state of industrial floor systems and their final adjustments to increase its mechanical and chemical resistance. At the same timethis thesis focuses on the possibilities of using secondary raw materials in the development of new industrial floors. The goal is to partly replace the silicate binder in the raw material mix of cement screed with a secondary raw material to achieve the same or better physical and mechanical characteristics. This part is also verified experimentally, and its conclusion is to design an optimal recipe of screed by using secondary raw materials.
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Development of cement-bonded particleboards with modified matrix composition
Konečný, Dalibor ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
In manufacture of cement-bonded particle boards are in present-days used exclusively wooden particles as filler. This thesis deals with a research of possible substitution of this material, especially of waste emerging by production of CBPB itself. At first is completed a survey of possible substitute fillers and czech and foreign literature, dealing with issues of modification of composition of cement-bonded particle boards. In practical part are tested some treatments of waste and its adding to recipe. Further are analysed the influences of substitution of cement by slag and substitution of wooden particles by recycled fibreglass. By laboratory work with CBPB is monitored the influence of amounts of added wather to fresh mixture and also to properties of finished elements.
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Development of repair mortar with resistance to high temperatures
Šottl, Jiří ; Gross, Tomáš (referee) ; Bydžovský, Jiří (advisor)
Currently, increasing reinforced concrete structures and concrete structures that require repair in the form of remediation. The master’s thesis deals with the development of repair mortars with resistance to high temperatures, which would allow the re-profiling of the fire damaged parts of the structures and restore its function. Development of repair mortars is based on a literature review of articles dealing with research materials resistant to high temperatures.
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