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Testing of binders of thermal insulations for specific applications on technical appliances
Maňák, Jan ; Kulísek, Karel (referee) ; Petránek, Vít (advisor)
This work focus on testing alcali-activated binders for thermal insulation which could be used for special industry devices. In the beginning of this work is presented example of thermal energy storage where these specific alcali-activated materials can be used. Ensuingly two construction with thermal energy storage tanks are mentioned. Most of the interest aims on ageing and rheological properties of alcali-activated binder. Some rheological methods are also discussed. In the end of this work is added practical experience.
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Influence of type of base sand on strength of geopolymer sand mixture
Kudr, Martin ; Šupálek, Milan (referee) ; Cupák, Petr (advisor)
The goal of this research is to find out the effect of different types of opening material on bending strength geopolymer’s moulding mixture. Four different silical opening material were used along with two types of binder. To solve the selected problem I have used the test of bending strength. At first I have prepared the moulding mixture and after its induration, I have tested the bending strength. The times were always the same 60, 120 and 1440 minutes. The highest level of bending strength was achieved at opening material SH-34 when using binder Geopol 618. The value of bending strength level was 0,881MPa. The results of this research could help the foundries during implementing technology of geopolymer moulding mixture, which would help particulary when looking for a proper opening material.
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Color possibilities of artificial sandstones based on geopolymers
Lattenberg, Pavel ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
This thesis deals with the possibility of preparing artificial sandstone based on geopolymer matrix and ways to achieve a natural appearance and good mechanical properties. The theoretical part is devoted to the current state of knowledge in the field of geopolymers and their recovery potential, but also the natural sandstone and its geographic diversity. The practical part deals with the preparation of various types of binding systems based on metakaolin, ground blast furnace slag and water glass. Their comparison, and the possibility the appearance and characteristics change in the composition of the filler.
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The possibilities of using of foundry filter ash
Solik, Jaroslav ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
This thesis explores the posibility of using of foundry filter ash for production of inorganic composite materials, that could be used primary in the construction industry. The thesis is divided into theoretical and experimental section, where theoretical section contain literature review of used materials and the experimental section summarizes the results of laboratory tests performed on tested mixture based on portland and alumina cement with various content of foundry filter ash. For comparison was also used another foundry waste - foundry sand. Prepared test bodies with dimension of 40 x 40x 160 mm was subjected to mechanical strength tests and the influence of amount of foundry waste on the strenght of the prepared mixtures was monitored. Next the thesis deals with possibilities of alkaline activation of foundry waste, where sodium water glass, sodium hydroxide and commercially supplied baucis L 160 component B were used as alkaline activator. These test mixtures were also subjected to mechanical strenght tests and the influence of amount of foundry waste on the strenght was observed too. The analysis of input materials were performed by XRF, TG – DTA – EGA and XRD powder diffraction methods. All strength tests were tested by testing equipment desttest 4310.
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Thin-film geopolymeric plasters for exterior application
Ručková, Jana ; Opravil, Tomáš (referee) ; Šoukal, František (advisor)
This thesis is dealing with preparation of exterior thin-layer geopolymer plaster where the effect of supplement of various types of superplasticizers in their different amounts on the quality of geopolymer plaster is studied. The objective of this work is to determine suitable type of superplasticizer which would improve rheological quality of fresh plaster mix, its adhesion to the surface and last but not least would preserve good mechanical qualities of geopolymer binder. In the experimental part initially test subject were prepared from meta-kaolin, water, water-glass, sand and with supplement of various types of superplasticizers in various amounts. These test subjects were tested for compressive and flexural strength. Further workability and adhesion to the surface of these plaster pastes was observed. Geopolymer pastes were also subjected to calorimetric comparison of kinetic processes occurring during solidification and hardening. In order to identify the exact composition of superplasticizers used as rheological modifiers, the infra-red spectrometry of these substances was performed. There was a need to specify the water-glass in more detail as well, elemental analysis was performed on it on radiographic fluorescent spectrometry. To closer identify the structure and distribution of superplasticizer in geopolymer paste the pictures of the mix which was the most suitable for use for exterior thin-layer geopolymer plasters were made on scanning electron microscope. On the same mix radiographic diffraction on the powder samples was also performed which served for phase analysis.
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Research of interface between quartz and non quartz mould materials grains and geopolymer binder
Skřivánková, Vendula ; Burian,, Alois (referee) ; Cupák, Petr (advisor)
Presented thesis deals with monitoring of the properties of the interface between opening materials and geopolymer binder using three quartz and four non quartz opening materials. There is observed mainly the type of destruction of connective bridges. The theoretical part of the thesis briefly summarizes commonly used methods in foundries and monitors experience with implementation of geopolymers in different foundries. The practical part monitors shape of the grains of the chosen opening materials. There are writed down the results from the measurement of the bending strength and workability and there is observed the type of destruction of connective bridges.
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Modification of concrete elements for cooling towers
Mohelská, Lucie ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
This master´s thesis deals with the suppression of the growing of algae in cooling towers. Subject of the work is suggestion and testing surface modification of the existing mature concrete in order to suppress the growth of algae. In the frame surface modification, several commercially available and newly developed systems were tested. Testing systems are based on the basis of portland cement, geopolymers or formation of insoluble complex compounds containing metal elements (Zn, Cu). Experimental methods were applied in the real environment of cooling towers of Dukovany Nuclear power plant.
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The development of composites based on inorganic binders designed for the extreme applications
Janoušek, Petr ; Šácha, Libor (referee) ; Dufka, Amos (advisor)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
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Study of synthetic sandstones preparation possibilities
Solik, Jaroslav ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
This thesis explores the possibility of developing synthetic sandstones based on alkaline-activated (geopolymer) binders. The goal is to design an appropriate connective system of optimal concentration, so that the prepared material (artificial stone) showed similar characteristics as natural. The experimental section summarizes the experiments that explore several different alkali connective systems. The aim is to compare the properties of binders prepared from methakaolin (Mefisto K-05 and L-05) alkali-activated by sodium or potassium water glass. For comparison with these connective systems were also prepared samples of commercially supplied geopolymer binder called Baucis
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