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The influence of zinc oxide on the cement composite with silica fume.
Dobiáš, Jiří ; Koutný, Ondřej (referee) ; Šiler, Pavel (advisor)
The aim of this work was to investigate the influence of zinc oxide on the properties of blended Portland cement mixed with silica fume. On the pastes were monitored flow properties and by using of isoperibolic calorimetry process of the hydration. On the prepared samples were studied mechanical properties of obtaining values of compressive and flexural strength after 1, 7 and 28 days. By using of XRD were measured phase composition and microstructure development war observed by SEM. The elemental composition of cement leaches was measured by using of ICP-OES.
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The Study of Aditives and Admixture Influence on High-Performance Concrete Properties
Šiler, Pavel ; Bílek, Vlastimil (referee) ; Brandštetr, Jiří (referee) ; Havlica, Jaromír (advisor)
The aim of this work was to develop the method for the determination of the superperplasticizers (SP) content in the water solution. The method developed was then applied to study the SP adsorption on the individual components used for high-performance concrete and the influence of the temperature and pH values over this adsorption. Furthermore the influence of the water to binder ratio, SP, finely grounded granulated blast furnace slag, fly ash, silica fume, finely ground silica sand and bauxite on the hydration process was studied by means of isoperibolic, isothermal and solution calorimetry. The compressive and flexural strength of most samples used in calorimetric experiments was also determined.
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Rheology in Technology of Inorganic Binders
Kosár, Petr ; Másilko, Jiří (referee) ; Zmrzlý, Martin (advisor)
This final thesis deals with the study of rheological behaviour of cement pastes. The introductory part describes the composition of Portland cement. Next, a detailed description of mutual interaction between cement and water and the principle of superplasticizer affection follows. The thesis includes a description of properties and interaction of alumina cement with water as well as rheological properties of suspensions and cement pastes. Finally, the theoretical part provides a survey of the elementary methods and equipment for the evaluation of rheological properties of cement materials. The experimental part includes measurement and evaluation of rheological properties (flow curves, plastic viscosity and yield stress) of cement pastes with different composition. The influences of water-cement ratio, amount of superplasticizer and the kind of cement on rheological properties of cement pastes are compared here.
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The influence of heavy metal oxides on the properties of cement pastes
Kašpárková, Kateřina ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The Bachelor´s thesis is focused on study of the effect of increased content of heavy metals in cement production on the properties of this cement and the effect of addition of heavy metal oxides in cement pastes production. The thesis also deals with structural changes in particular components of cement in the presence of heavy metals. The effect of addition of heavy metal oxides on the properties of cement pastes is demonstrated in the experimental part by determining their mechanical properties, pore structure, and observation of the progress of hydration.
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