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Economic aspects of environmental use of building materials based on secondary raw materials.
Ťažký, Tomáš ; Durica,, Tibor (referee) ; Sedlmajer, Martin (referee) ; Nosek,, Karel (referee) ; Kulísek, Karel (advisor)
The disses thesis is focused on usage of secondary raw materials from the electric power industry, specifically fly ash as a component for the building industry, concentrated on concrete. Two main streams are covered, environmental and economical. Reasons, which led to focus on the selected subject are coming mainly from the scarcity and availability of high-quality mineral resources, environmental pressure for usage of industry byproduct, reducing emissions and economical pressure to reduce production cost, especially raw materials. The main purpose of the work was to verify the possibility of increasing the usability of fly ash as a mineral additive in the technology of concrete production with materials retrieved from coal fired power plants and applying mechanical activation of fly ash. The main goal of the experimental part of work was to demonstrate improvement of fresh and hardened concrete properties as a main condition to support economic efficiency of mechanical activated fly ash. Base on previous facts the methodology was covering two main areas, the experimental and the assessment. Relatively large sets of tests were performed, using a wide range of tested high temperature fly ash and fluidized bed combustion fly ash granulometrically treated, by mixing and grinding. Results of the testing confirmed focused parameters for concrete and mortar mechanical properties, total economical efficiency of the targeted solution and the subject of the dissertation. In the experiment section has been retrieved valuable findings contributing to the overall knowledge of the faculty, also for the practical application. The results of the tests confirmed the achievement of the planned target parameters, both in terms of physical and mechanical properties of experienced mortars and concretes, as well as the overall economic efficiency of the proposed design and the topic of the disses thesis. Within the experimental work, valuable professional knowledge and benefits w
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The binder based on the high-calcium ash - the influence of the alkali activator
Šichnárek, Vojtěch ; Kotrla, Jan (referee) ; Koplík, Jan (advisor)
The aim of this thesis was examination of the influence of different alkali activators to final properties of binders based on fluidized bed combustion fly ash. There were prepared mixtures containing sodium waterglass or sodium carbonate. Curing time, consistence, and strengths after 2, 7, 14 and 28 days were measured. X-ray diffraction and X-ray fluorescence were used to find out the composition of samples. There were taken images and element spectra using scanning electron microscope and isothermal calorimetry was used to determine the heat flow during the time of curing. The results indicate that the use of water glass achieves better initial workability and pressure strengths are higher than besides sodium carbonate. However, when sodium carbonate is used, pressure strengths are lower, but they are less dependent on the amount of the activator and do not change as much with time. Crystallographic composition is dependent to the activator used – by using sodium waterglass there was more of ettringite and portlandite in the sample.
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Possibilities of reducing shrinkage of concrete and development of concrete recipes with limited shrinkage.
Stoklásek, Martin ; Louda,, Pavel (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with the issue of volume changes of concrete and their causes. The theoretical part describes the various types of volume changes in concrete and the causes of their occurrence. Influence of concrete mix design and concreting conditions on volume changes. Methods for reducing volume changes are also addressed. The experimental part is focused on the development of recipes with limited volume changes. In which the development of shrinkage is monitored from an early age up to 60 days and at the same time the development of compressive strengths at 2, 7, 28 and 60 days is also monitored.
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: Development of special high strength concrete with low volume changes
Meruňka, Milan ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with problems of volume changes of concrete, especially shrinkage of concrete. Types of concrete changes, causes, occurrences, and ways to eliminate them are described. The experimental part is focused on monitoring the volume changes of concrete within 28 days of maturing using a different type and dose of shrinkage reducing additions, a summary of cement pastes within 24 hours of mixing, the development of temperatures of the hydration temperatures of concrete and cement pastes.
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Possibilities of reducing shrinkage of concrete and development of concrete recipes with limited shrinkage.
Stoklásek, Martin ; Louda,, Pavel (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with the issue of volume changes of concrete and their causes. The theoretical part describes the various types of volume changes in concrete and the causes of their occurrence. Influence of concrete mix design and concreting conditions on volume changes. Methods for reducing volume changes are also addressed. The experimental part is focused on the development of recipes with limited volume changes. In which the development of shrinkage is monitored from an early age up to 60 days and at the same time the development of compressive strengths at 2, 7, 28 and 60 days is also monitored.
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Economic aspects of environmental use of building materials based on secondary raw materials.
Ťažký, Tomáš ; Durica,, Tibor (referee) ; Sedlmajer, Martin (referee) ; Nosek,, Karel (referee) ; Kulísek, Karel (advisor)
The disses thesis is focused on usage of secondary raw materials from the electric power industry, specifically fly ash as a component for the building industry, concentrated on concrete. Two main streams are covered, environmental and economical. Reasons, which led to focus on the selected subject are coming mainly from the scarcity and availability of high-quality mineral resources, environmental pressure for usage of industry byproduct, reducing emissions and economical pressure to reduce production cost, especially raw materials. The main purpose of the work was to verify the possibility of increasing the usability of fly ash as a mineral additive in the technology of concrete production with materials retrieved from coal fired power plants and applying mechanical activation of fly ash. The main goal of the experimental part of work was to demonstrate improvement of fresh and hardened concrete properties as a main condition to support economic efficiency of mechanical activated fly ash. Base on previous facts the methodology was covering two main areas, the experimental and the assessment. Relatively large sets of tests were performed, using a wide range of tested high temperature fly ash and fluidized bed combustion fly ash granulometrically treated, by mixing and grinding. Results of the testing confirmed focused parameters for concrete and mortar mechanical properties, total economical efficiency of the targeted solution and the subject of the dissertation. In the experiment section has been retrieved valuable findings contributing to the overall knowledge of the faculty, also for the practical application. The results of the tests confirmed the achievement of the planned target parameters, both in terms of physical and mechanical properties of experienced mortars and concretes, as well as the overall economic efficiency of the proposed design and the topic of the disses thesis. Within the experimental work, valuable professional knowledge and benefits w
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The binder based on the high-calcium ash - the influence of the alkali activator
Šichnárek, Vojtěch ; Kotrla, Jan (referee) ; Koplík, Jan (advisor)
The aim of this thesis was examination of the influence of different alkali activators to final properties of binders based on fluidized bed combustion fly ash. There were prepared mixtures containing sodium waterglass or sodium carbonate. Curing time, consistence, and strengths after 2, 7, 14 and 28 days were measured. X-ray diffraction and X-ray fluorescence were used to find out the composition of samples. There were taken images and element spectra using scanning electron microscope and isothermal calorimetry was used to determine the heat flow during the time of curing. The results indicate that the use of water glass achieves better initial workability and pressure strengths are higher than besides sodium carbonate. However, when sodium carbonate is used, pressure strengths are lower, but they are less dependent on the amount of the activator and do not change as much with time. Crystallographic composition is dependent to the activator used – by using sodium waterglass there was more of ettringite and portlandite in the sample.
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: Development of special high strength concrete with low volume changes
Meruňka, Milan ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with problems of volume changes of concrete, especially shrinkage of concrete. Types of concrete changes, causes, occurrences, and ways to eliminate them are described. The experimental part is focused on monitoring the volume changes of concrete within 28 days of maturing using a different type and dose of shrinkage reducing additions, a summary of cement pastes within 24 hours of mixing, the development of temperatures of the hydration temperatures of concrete and cement pastes.
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Activation of high ash addition of fly ash for concrete production fluid
Ťažký, Martin ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
Secondary energy products are used in the construction industry for a long time. More strict environmental limits for emissions to air have created new technologies combustion of materials in thermal power plants. In this way combustion are produced a new secondary energy products. It is an attempt to find of suitable use for these products. Their use will have ecological impact on the environment and it will allow prepare of new compositions of higher utility properties. The aim of this study was to develop a new mixture, using the new secondary energy products, for production concrete with high utility properties.
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The development of high performance concrete with secondary raw materials
Osuská, Lucia ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
The thesis is focused on the possibility of using secondary energy resources as an additive to concrete to improve some of its resulting properties. The theoretical part is devoted to the problems of shrinkage and prominence hydration process during hydration of the concrete. This section also contains the results of research work from domestic and foreign sources of high temperature fly ash and fluidized bed combustion fly ash use and their using in concrete. The practical part verifies the possibility of using these materials and their combination as an additive to concrete with impact on the physical and mechanical properties.
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