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Study of the influence organic fibres on the fire resistance of concrete
Klobása, Jan ; Přikryl, Jan (referee) ; Sedlmajer, Martin (advisor)
The master thesis is focused on current issues of concrete behaviour under high temperatures. In the theoretical part, a search of knowledge about changes in concrete, which take place when exposed to thermal loads, which simulates the effect of fire, is performed, and summarized. It is also important to summarize the changes in the individual components that are used to produce concrete. This work describes the effect of high temperatures on mechanical and physical properties as well. There is an information about the most used fibres and their function in concrete. Emphasis is placed on describing the possibility of using recycled PET or cellulose fibres due to the positive environmental impact. In the experimental part, recipes with different types and amounts of fibres are proposed. The subject of the research was to determine how individual types and amounts of fibres affect the physical mechanical properties of concrete and their suitability for use at high temperatures. Microscopic scanning and study of changes in the structure of concrete was also performed.
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Study of fibres behaviour in cement composite
Nešporová, Tereza ; Křížová, Klára (referee) ; Sedlmajer, Martin (advisor)
Bachelor thesis is focused on behavior of fibers on selected properties of fine–grained cementitious composite in fresh and hardened state. The emphasis is on usage of enviromentaly friendly fibers, specifically fibers obtained from recycled materials. Different fibres in cement composites are compared in terms of geometry and material base. The findings at the theoretical level are summarised, including information from scientific studies. Practical determination of selected properties on fresh composite such as consistency and shrinkage of the material is covered. Mechanical properties such as flexural tensile strength and compressive strength are also determined. The water permeability is also investigated.
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Use of organic fibers in fine-grained cement composites and their influence on the monitored properties
Mazán, Tomáš ; Ondráček, Michal (referee) ; Křížová, Klára (advisor)
The diploma thesis describes the possibilities of using organic fibres to improve the properties of cement composites at high temperatures. The theoretical part of the thesis deals with the behaviour of the different components of concrete and concretes in fire. A substantial part is devoted to the types of fibres, the method of dosage and the effect of their use on selected parameters. The practical part of the thesis is based on the developed methodology. On the basis of the results obtained, a summary of the behaviour and transformations of different types of organic fibres when exposed to temperatures from 20 to 800 °C was compiled. Furthermore, the observed parameters and the effect of the fibres, especially on the strength of the composite loaded at high temperature, are evaluated. The final of thesis concludes with recommendations for fibre dosage and the suitability of using recycled fibres.
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Study of the influence organic fibres on the fire resistance of concrete
Klobása, Jan ; Přikryl, Jan (referee) ; Sedlmajer, Martin (advisor)
The master thesis is focused on current issues of concrete behaviour under high temperatures. In the theoretical part, a search of knowledge about changes in concrete, which take place when exposed to thermal loads, which simulates the effect of fire, is performed, and summarized. It is also important to summarize the changes in the individual components that are used to produce concrete. This work describes the effect of high temperatures on mechanical and physical properties as well. There is an information about the most used fibres and their function in concrete. Emphasis is placed on describing the possibility of using recycled PET or cellulose fibres due to the positive environmental impact. In the experimental part, recipes with different types and amounts of fibres are proposed. The subject of the research was to determine how individual types and amounts of fibres affect the physical mechanical properties of concrete and their suitability for use at high temperatures. Microscopic scanning and study of changes in the structure of concrete was also performed.
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