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Plasters modified by burnt clays
Soukupová, Eva ; Příhoda,, Jiří (referee) ; Sokolář, Radomír (referee) ; Michoinová,, Dagmar (referee) ; Rovnaníková, Pavla (advisor)
The doctoral thesis deals with the reactivity of burnt clays in connection with modified lime mortars. The theoretical part of the doctoral thesis provides an overview of the properties of lime mortars, their quality and ways of their degradation. The different types of burnt clays (brick powder, bentonites and burnt clay shale), their origin, properties and factors affecting their reactivity and methods of its evaluation are stated. The properties and reactivity of burnt clays are evaluated on the basis of determination of pozzolanic activity, mineralogical and chemical composition, surface area, density, content of the amorphous phase and granulometry in the experimental part of the doctoral thesis. The compositions of lime mortars containing burnt clays and evaluation of an impact of burnt clay on the properties of mortars in the fresh and hardened state are given. Consistency, bulk density, workability and air content of mortars in the fresh state are evaluated. Strength characteristics depending on the time, water absorbability, porosity, capillary attraction, adhesion, coefficient of diffusion resistance, frost resistance, shrinkage, mineralogical composition and microstructure of mortars in the hardened state are evaluated. Attention is also paid to the influence of the cellulose ether addition into the modified lime mortars.
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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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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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Latex Modified Cement Composites
Kunc, Michal ; Rovnaníková, Pavla (referee) ; Kuřitka, Ivo (referee) ; Havlica, Jaromír (advisor)
The subject of dissertation is a study of physic-mechanical properties and development of self-leveling polymer-cement composite of the ternary binder system PC-CAC-CS modified with chemical additives and polymeric substances. The dissertation systematically describes a four-step optimalization of the composite considering its key properties. Experimental part has been focused on monitoring the impact of composite components on selected final properties. Basic physico-mechanical, structural properties and its relations (compressive strength, porosity, flow abilities, setting times) have been analyzed for deeper understanding of the effects of individual composite components. Methods which quantify the existence of the newly formed hydration product – ettringite (XRD, SEM with EDS, calorimetry, dilatometry) has been chosen as additional study methods on selected combinations. A working prototype of self-leveling polymer-cement composite was successfully developed based on systematic process and using of testing procedures and measuring methods.
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Application of metakaolin in refractory materials
Tvrdík, Lukáš ; Rovnaníková, Pavla (referee) ; Havlica,, Jaromír (referee) ; Kutzendőrfer,, Jaroslav (referee) ; Lang, Karel (advisor)
Refractory materials are irreplaceable in all industrial fields where it is necessary to use high temperatures. This paper deals with the use of metakaolin in refractory materials that allows the operation of such facilities. In recent decades has the development made significant progress in quality parametres, which extended life period of refractory materials in their use and significantly decreased the specific consumption of refractory materials in various technologies. This phenomenon is also called "harakiri effect". At the same time a constant pressure to the lowest prices of products is on the refractory market. Metakaolin seems to be appropriate raw material, which may help to achieve interesting qualitative effects. It may affect many properties of the influence on the behavior of materials during processing, through physico-mechanical parameters and dipping to the economic efficiency of production.
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Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortar
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
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The effect of aggregate type on the properties of lime mortar
Žižlavský, Tomáš ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The thesis is focused on the comparison of the role of different types of aggregates and the binder-aggregate ratio on the properties of lime mortars. The theoretical part of the thesis deals with the effect of properties of aggregate, a binder-aggregate ratio and a use of calcareous aggregate, especially limestone, on the properties of mortars. It also deals with the utilization of limestone as aggregate in a history of masonry. In the practical part of the thesis there is a comparison of physically-mechanical and microstructural properties of mortars prepared with different type of aggregate (siliceous sand and limestone aggregate), with varying binder-aggregate ratio and also with a partial substitution of the aggregate by limestone fines. It was found that the usage of limestone instead of quartz sand produces the mortar of comparable properties. The partial substitution of the aggregate with limestone fines caused noticeable growth of strength, especially in mortars with higher binder-aggregate ratio.
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Properties of Zeolites and Their Use in Building Binders
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
Zeolites, such as natural or synthetic aluminosilicates, have a wide range of applications. Their application in the construction industry tends to use zeolites as impurity type II. However, it has to prove their reactivity and affect the content of calcium hydroxide in the concrete. The aim is to determine the effect of zeolite as a partial replacement of cement in different concentrations on the mechanical properties of fine-grained concrete and consumption of calcium hydroxide.
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Lime mortars with the addition of ground limestone
Žižlavský, Tomáš ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The thesis is focused on an effect of addition of ground limestone on properties of lime based mortars. Theoretical part of the thesis deals with diferenciation of plasters and their utilization, history of using limestone as an aggregate, its exploitation in the present and its impact on properties of lime based plasters, specially on strenghts. In the next part there's elaborated the carbonation reaction including the influence of external agents. Practical part of the thesis is focused on proving assumtions from theoretical part, particulary on the influence of ground limestone on the strenght properties of lime based plasters.
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