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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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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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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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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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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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Solidifikace ionesu s přídavkem dastitu v geopolymerné matrici
Černoušek, T. ; Hendrych, J. ; Sobek, Jiří
Solidification of ion exchange resins is specific in comparison to other liquid and solid RAW for all that use geopolymers, cements or other inorganic matrix. In contact with water the unsaturated ion exchange resin the swelling occures and internal pressure arises, and can reach up to 50 MPa. These changes can disrupt the process of solidification, cause cracks, which finally deteriorate the solidificate leaching parameters and lead to a decrease weight ratio of ion exchange resin to binder. To increase the loading capacity of ion exchange resin into the geopolymer the additive representing highly absorbent material Dastit has been tested, in terms of mechanical properties.
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