|
|
The development of high-strength concrete with a high content of el. fly ash
Roubal, David ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with the study of high-strength, high-volume fly ash concrete. The theoretical part of this thesis focuses on the detailed characteristic and main principles of high-strength concrete, high-volume fly ash concrete. In addition, according to the findings, the technology of high-strength and high-volume fly ash concrete, including principles of high strength, has been described. On the basis of the findings, high-strength, high-volume fly ash concrete for specific compressive strengths has been designed and created in the experimental section. These concretes were then subjected to a number of tests.
|
|
|
Investigation of portlandite carbonation using the in-situ X-ray diffraction analysis
Růžička, Lukáš ; Koplík, Jan (referee) ; Másilko, Jiří (advisor)
Thesis deals with carbonation of portlandite using in-situ X-ray diffraction analysis. The carbonation of portlandite progress in concrete structures and it is already quite widely discussed. It is responsible for corrosion and degradation of reinforced concrete elements, and thus its influence is perceived very negatively. The main goal of this work is to determine the ideal conditions for the progress of carbonation of portlandite. In this work the progress of carbonation depending on the relative humidity and temperature was observated. The amount of carbonated portlandite was evaluated by means of thermal analyzes (TG / DTA) and X-ray analysis.
|
|
|
Study of microstructure of autoclaved aerated concrete with using of secondary raw materials
Martanová, Jana ; Suchý, Peter (referee) ; Kulísek, Karel (advisor)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.
|
|
|
Mechanism and kinetics of gas-solid carbonation of portlandite
Valach, Jakub ; Švec, Jiří (referee) ; Ptáček, Petr (advisor)
The main goal of this work, is study of kinetics and mechanism of gas-solid carbonation of portlandit. The introduction part of the thesis acquaints the reader with basic theoretical information about the study of kinetics, mechanism and the analyses themselves. In the experimental part, the reader is acquainted with the methods and procedures used to evaluate the kinetics and mechanism. The last chapter interprets the results of the study, with discusion about results and analysis of the used sample.
|
|
|
The development of high-strength concrete with a high content of el. fly ash
Roubal, David ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with the study of high-strength, high-volume fly ash concrete. The theoretical part of this thesis focuses on the detailed characteristic and main principles of high-strength concrete, high-volume fly ash concrete. In addition, according to the findings, the technology of high-strength and high-volume fly ash concrete, including principles of high strength, has been described. On the basis of the findings, high-strength, high-volume fly ash concrete for specific compressive strengths has been designed and created in the experimental section. These concretes were then subjected to a number of tests.
|
|
|
Study of microstructure of autoclaved aerated concrete with using of secondary raw materials
Martanová, Jana ; Suchý, Peter (referee) ; Kulísek, Karel (advisor)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.
|
|
|
Investigation of portlandite carbonation using the in-situ X-ray diffraction analysis
Růžička, Lukáš ; Koplík, Jan (referee) ; Másilko, Jiří (advisor)
Thesis deals with carbonation of portlandite using in-situ X-ray diffraction analysis. The carbonation of portlandite progress in concrete structures and it is already quite widely discussed. It is responsible for corrosion and degradation of reinforced concrete elements, and thus its influence is perceived very negatively. The main goal of this work is to determine the ideal conditions for the progress of carbonation of portlandite. In this work the progress of carbonation depending on the relative humidity and temperature was observated. The amount of carbonated portlandite was evaluated by means of thermal analyzes (TG / DTA) and X-ray analysis.
|
guest ::
