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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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Preparation of geopolymeric binders for toxic metals inhibition
Jevická, Lucie ; Kalina, Lukáš (referee) ; Šoukal, František (advisor)
This thesis deals with preparation of geopolymeric binders for inhibition of toxic elements, especially arsenic. It studies influence of content progress of different phases in prepared binders on leachability of As during the setting. The aim of this study is to determine the type of inhibition or the cause of leachability of As in prepared binders respectively. Fly ash from high-temperature coal combustion, slag, cement kiln dust and sodium hydroxide solution were used for experimental works. FT-IR, TG-DTA, XRD analyses after different hydration times were used. The leachates were analyzed by ICP-MS. Calorimetric measurements of tested mixtures fresh pastes were implemented to learn about setting process. Hardened binder specimens were tested for bending and compressive strength.
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Composite materials based on alcali activated blast furnace slag with admixture of fly ash
Indra, Ivo ; Brandštetr, Jiří (referee) ; Opravil, Tomáš (advisor)
This thesis concerns on substitution of blast furnace slag or its part with fly ash in alkali-activated systems based on aluminosilikates. Classic, fluid bottom and fluid filter fly ashes will be tested. The goal is to prepare geopolymer with required mechanical properties, but with maximal admixture of alternative raw materials. In composites with substitutioned slag or its part the thesis focuses mainly on workabilityof fresh mixture, pressure and bending strenght. Use of secondary raw materials has advantages in the economic point of view and it´s friendly to enviroment, too.
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Preparation of hystorical geopolymers
Šrámková, Eva ; Šoukal, František (referee) ; Havlica, Jaromír (advisor)
Diploma thesis studies historical bonding agents on the base of geopolymers. The aim of the thesis is to find a proper material composition, especially made of natural clay materials (kaolinite, bentinite) and their modifications (metakaoline). These bonding agents have to have a suitable type of an activator that guarantees good bonding properties. Therefore testing of various kinds of alkaline activating ingredients on the same mineral composition was done. Except of usual hydroxides and a water glass, ancient natrons (mixtures of alkaline carbonate with addition of appropriate chlorides) and a lime mash were used as the activators. From the above mentioned mixtures, series of samples (columns 20 x 20 x 100 mm) stored at the laboratory temperature were prepared. In the prepared mashes, their workableness and moulding were investigated. In the developed samples, their surface appearance was observed together with a number of efflorescence and its types. An indivisible part of the research was formed by determination of mechanical properties of the experimental columns such as a compressive strength and a tensile strength in bending. Furthermore, phase composition of the samples and its changes with a temperature increase were investigated. For these tests, XRD and TG – DTA methods were used. A multi-seat isoperbolic calorimeter was used to study hydratation that was also the important part of the general evaluation of designed mixtures.
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Reduction of efflorescence in the geopolymer systems
Suchý, Rostislav ; Šoukal, František (referee) ; Kalina, Lukáš (advisor)
Alkali metal cations are weakly bound in the structure of alkali activated materials. This fact causes the formation of undesirable efflorescence in humid environment. In this work, the effect of fluoride additives, which significantly reduce the efflorescence, was investigated. The chemical mechanism of selected additive in the modified binder was studied based on XRD, SEM EDX and ICP OES analysis. Also the effect of the added fluorides on the mechanical properties of the final product was monitored.
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Optimization of concrete mixture based on alkali activation of secondary materials
Šafář, Martin ; Šoukal, František (referee) ; Kalina, Lukáš (advisor)
This bachelor thesis deals with design, preparation and optimization of concrete mixture based on alkali activated secondary materials – blast furnace slag and fly ash. Sodium hydroxide partially replaced by bypass cement kiln dust was used as an activator. Mixture design was based on model made for Portland cement based concrete. Observed properties were workability of fresh mortar, price of mixtures and mechanical properties of concrete. Microstructure and composition of concrete was studied by SEM-EDX and XRD. Analysis of raw materials was based on XRF. The optimal mixture composition was chosen from obtained data.
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Reinstating of concrete floors on alkalic way
Straděj, Tomáš ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
The work deals with the reinstanting of concrete floors by alkali way. The section deals with concrete, its development, production, use, and substances from which it is made. The second part deals with connective systems based on portland cement concrete flooring applications and possibilities of their reinstanting through alkaline. The thesis proposal for the reinstanting of the floor and describes the laboratory experiment.The last part contains information of practical measurements and conclusions drawn regarding the suitability of repair methods and resources for concrete floors different alkali and their combinations.
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