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Influence of Zinc in Byproducts on Hydration and Properties of Blended Portlands Cements
Šilerová, Iva ; Palou, Martin (referee) ; Rovnaníková, Pavla (referee) ; Havlica, Jaromír (advisor)
The theme of this work is to monitor the effect of zinc on the properties of blended Portland cements. Zinc was tested in the form of two-soluble salts: Zn(NO3)22 H2O and ZnCl2 and a very slightly soluble compound ZnO. Blended cements were prepared by partial replacement with finely ground granulated blast furnace slag, high-temperature and fluidized bed combustion filter fly ash. Flow properties were studied on the prepared pastes. Impact on hydration reactions was examined by using of isothermal and isoperibolic calorimetry. Flexural and compressive strength were measured as mechanical properties of the prepared test specimens. The phase composition of the prepared composites and incorporation of zinc ions in the cement matrix via leaching tests and FTIR analyzes were also studied. Microstructure development of cement samples was tested by SEM analysis with EDS. Influence on ecotoxicity was also measured.
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Optimizing the composition of micro concrete admixtures.
Juříková, Denisa ; Křížová, Klára (referee) ; Hela, Rudolf (advisor)
The aim of this paper is to summarize knowledges related to the use of fine-grained admixtures in cement composites. By utilizing of these admixtures it is possible to achieve extreme properties, especially high strenght and durability of concrete. These properties can be achieved by optimizing the density of the binder and filler in range of 0 to 0,25 mm. Therefore, large part of thesis is focused on admixtures and its effect on concrete. The experimental part of the thesis deals with optimization od selected admixtures in combination with cement to achieve the minimum of the voids and their compressive strenght were determined at 1, 3, 7, 28 and 60 days.
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The study of zinc influence on Portland cement hydration.
Ptáček, Martin ; Janča, Martin (referee) ; Šiler, Pavel (advisor)
The topic of this work is the monitoring of the effect of zinc on the hydration process in Portland mixed cement (specifically with the addition of finely ground granulated blast-furnace slag, high temperature fly ash and fluidized bed combustion filter ash). How much zinc and at what time it remains in the pore solution during hydration. Activation energy of a mixture of cement with zinc in the form of soluble salts (Zn(NO3)2.6H2O and ZnCl2) and insoluble oxide (ZnO) by isothermal calorimetry was also investigated. The XRF method has shown composition during hydration. The zinc retardation effect was investigated by isothermal calorimetry and activation energy was calculated using this method. The XRF and ICP-OES methods were used to measure the zinc content of the pore solution. And the amount of portlandite was monitored by the DTA and XRF method.
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Study of the concept of K-value and efficiency index for fly ash and slag and their assessment and determination for concrete
Šperling, Petr ; Hela, Rudolf (referee) ; Hubáček, Adam (advisor)
This bachelor thesis deals with the use of active admixtures as a substitute for cement in concrete, specifically power plant fly ash and blast furnace slag. When using power plant fly ash and blast furnace slag as a substitute for cement in concrete, it is necessary to know their effect on concrete and to assess the different properties compared to concrete in which these admixtures are not used. This work will summarize the existing knowledge of the properties of power plant fly ash and blast furnace slag and their effect on fresh and hardened concrete. Furthermore, the possibilities of determining the efficiency index and the so-called k-value concept, which are used to assess the effect on cement mortar and concrete when replacing cement with an active admixture, will be summarized. In the experimental part, emphasis will be placed on determining the k-value. This is described in European technical standards in a very general way and is not sufficiently detailed for specific active ingredients.
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The study of zinc influence on Portland cement hydration.
Ptáček, Martin ; Janča, Martin (referee) ; Šiler, Pavel (advisor)
The topic of this work is the monitoring of the effect of zinc on the hydration process in Portland mixed cement (specifically with the addition of finely ground granulated blast-furnace slag, high temperature fly ash and fluidized bed combustion filter ash). How much zinc and at what time it remains in the pore solution during hydration. Activation energy of a mixture of cement with zinc in the form of soluble salts (Zn(NO3)2.6H2O and ZnCl2) and insoluble oxide (ZnO) by isothermal calorimetry was also investigated. The XRF method has shown composition during hydration. The zinc retardation effect was investigated by isothermal calorimetry and activation energy was calculated using this method. The XRF and ICP-OES methods were used to measure the zinc content of the pore solution. And the amount of portlandite was monitored by the DTA and XRF method.
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|
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Optimizing the composition of micro concrete admixtures.
Juříková, Denisa ; Křížová, Klára (referee) ; Hela, Rudolf (advisor)
The aim of this paper is to summarize knowledges related to the use of fine-grained admixtures in cement composites. By utilizing of these admixtures it is possible to achieve extreme properties, especially high strenght and durability of concrete. These properties can be achieved by optimizing the density of the binder and filler in range of 0 to 0,25 mm. Therefore, large part of thesis is focused on admixtures and its effect on concrete. The experimental part of the thesis deals with optimization od selected admixtures in combination with cement to achieve the minimum of the voids and their compressive strenght were determined at 1, 3, 7, 28 and 60 days.
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|
|
Influence of Zinc in Byproducts on Hydration and Properties of Blended Portlands Cements
Šilerová, Iva ; Palou, Martin (referee) ; Rovnaníková, Pavla (referee) ; Havlica, Jaromír (advisor)
The theme of this work is to monitor the effect of zinc on the properties of blended Portland cements. Zinc was tested in the form of two-soluble salts: Zn(NO3)22 H2O and ZnCl2 and a very slightly soluble compound ZnO. Blended cements were prepared by partial replacement with finely ground granulated blast furnace slag, high-temperature and fluidized bed combustion filter fly ash. Flow properties were studied on the prepared pastes. Impact on hydration reactions was examined by using of isothermal and isoperibolic calorimetry. Flexural and compressive strength were measured as mechanical properties of the prepared test specimens. The phase composition of the prepared composites and incorporation of zinc ions in the cement matrix via leaching tests and FTIR analyzes were also studied. Microstructure development of cement samples was tested by SEM analysis with EDS. Influence on ecotoxicity was also measured.
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