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The frost susceptibility of unbound mixtures to pavements
Surá, Kateřina ; Zajíček, Jan (referee) ; Stehlík, Dušan (advisor)
The thesis is focused on the analysis of the theoretical part of the unbound mixtures, their implementation and compliance. Further deals with determining the extent frost susceptibility direct and indirect method in the Czech Republic and the Member States of the European Union. The practical part is focused on the performance of tests on selected samples of unbound mixtures for which was gradually increased the content of fine particles and that direct and indirect method of determining the rate of frost susceptibility and also the evaluation of direct methods of particular customized way, which does not impose the appropriate standard. At the conclusion of the work is carried out an evaluation of the samples and comparison of the different methods with each other.
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Possibities to increase the frost resistance of brick body
Keršner, Štěpán ; Šveda,, Mikuláš (referee) ; Sokolář, Radomír (advisor)
This thesis, which comprises of a theoretical and a practical part, deals with possible means of increasing ceramic body frost resistance. The current state of research in the field of ceramic body frost resistance is summarized in the theoretical part. The practical part is divided into two sections. In the first section, the influence of firing temperature (820 °C and 1020 °C) and duration (2, 4 and 6 hours) on frost resistance and several other parameters is assessed by means of experiment, using a specimen of brick body made of mixes currently used in roof tile production by TONDACH Šlapanice and TONDACH Dolní Jirčany factories. In the second section of the practical part, two modifications are introduced of the mixture currently used in roof tile production in the TONDACH Šlapanice factory – GE clay and zeolite supplements were added, the effects of which are verified by means of experiment using specimens fired in a kiln designated for ceramic masonry blocks and alternatively in a kiln used for firing TONDACH Šlapanice roof tiles.
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The frost susceptibility of the soils and materials to subgrade of the pavements
Mašek, Jakub ; Zajíček, Jan (referee) ; Stehlík, Dušan (advisor)
This diploma thesis deals with the issue of the determination of the frost susceptibility of soils in the subgrades of road structures. The theoretical part compares the ways of testing the frost susceptibility in the Czech Republic and other selected countries of the European Union. Furthermore, it also deals with the development of the frost susceptibility index in the Czech Republic. The empirical part focuses on the laboratory testing of the frost susceptibility of the given sample of soil by the direct frost heave method. Moreover, it also deals with the simulation of penetration of frost by the subgrade and the possibility of shortening the length of the freezing during the direct testing the frost susceptibility.
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Substitution of silica filler in the correction mortars by artifical compact material
Jankovský, Július ; Opravil, Tomáš (referee) ; Havlica, Jaromír (advisor)
Master‘s thesis “Substitution of silica filler in the repair mortars by artifical compact material“ could by generally divided into two parts theoretical and experimental. The theoretical part is mainly focused on summarizing knowledge about repair mortars. The repair mortars are used for reprofilation of disrupted concrete layers, and therefore some of the most common defects of these layers, from which we can determine requirements for repair mortars are listed in the thesis. In the theoretical part, there is also mentioned a general formula of how to prepare a repair mortar, also there are described manufacture and characteristics of the most important ingredients of mortars such as cement, filler (aggregate), water and chemical modificators. Above all the theoretical part is focused on the effects that individual ingredients have on the resulting properties of repair mortars. The experimental part could be further divided into two parts. In the first part there are listed properties of the individual investigated materials and also there is introduced theoretical basis for particular tests of properties of repair mortars, such as analysis of grading distribution of a filler (aggragate), tests of flexular and compression strengths and frost resistance. In the first part there are also proposed formulae of mortar mixtures, where part of the original filler was substituted by an abrasive material TRYMAT, artificial compact aggregate made from blast furnace slag UHK d/D, or their combination. The properties of these mortar mixtures were compared to referential mortar mixture PANBEX R1. In the second part of experimental section is dedicated to summarization and discussion of the obtained results for individual mortar mixtures.
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Properties of cement composites with fiber reinforcement
Jankech, Filip ; Sitek,, Libor (referee) ; Bodnárová, Lenka (advisor)
This thesis summarizes the knowledge of the possibility of using organic fibres as dispersed reinforcement into cement composites. It is concretely a summary of knowledge about the types and properties of synthetic and cellulosic fibres, their influence on the properties of fresh and hardened cement composite and lastly a description of the fire resistance of cement composites and the effect of organic fibres on the action of those composites at high temperatures and in the presence of fire. The experimental part is supposed to verify the effect of the cellulose fibres on increasing the durability of the cement composite at high temperatures.
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