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Immobilization of heavy metals in the cement matrix with the admixture of natural zeolite
Semerádová, Nikol ; Bayer, Patrik (referee) ; Vyšvařil, Martin (advisor)
Heavy metals released to the natural ecosystem constitute significant risks not only for organisms, but also for water supplies in the nature. There are a number of analytical methods for the determination of heavy metals. Each of them is suitable for different element and its character. Since the results of the analysis are applied during the solidification and stabilization, it is necessary to ensure the highest correlation between hazardous waste and solidification medium for maximum inhibition of toxic ions. This work investigates the stabilization of heavy metals binders based on cement base with admixture of the natural zeolite and its possible use for the solidification of heavy metals in soluble form.
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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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Reological properties of cement pastes modified by amorphous SiO2
Zimmermann, Štěpán ; Rovnaník, Pavel (referee) ; Vyšvařil, Martin (advisor)
The subject of this thesis are the rheological properties of cement paste with the addition of amorphous silicon dioxide. The basic rheological parameters are that describe the behavior of cement pastes in the fresh state. The work also included rheological tests including measurement principle and method of evaluation. Effect of mineral admixtures with high content of amorphous SiO2 is summarized the available scientific articles. In the experimental part, the effects of impurities with a high content of amorphous SiO2 on the rheological properties of fresh cement paste. It was tested by substitution of up to 10 % by weight of cement in the cement pastes mineral admixtures of different chemical composition, particle size and pozzolanic activity. Flow measurement was measured yield value, viscosity, and flow index. The stability of cement pastes was investigated oscillatory measurements. To complement the behavior pastes in the fresh state was determined by calorimetry. Test results were compared with those determined by reference samples and compared the effect of various ingredients.
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Rheological properties of building binders in their fresh state
Hegrová, Michaela ; Rovnaník, Pavel (referee) ; Vyšvařil, Martin (advisor)
This thesis is devoted to the rheological properties of building binders. The theoretical part focuses on individual types of building binders, their rheological properties and basic parameters determinated during the rheological characterization of building binders. The practical part deals with the resultes obtained from the meansurements on a rotational rheometr using the geometry type of plate to plate. These results are subsequently evaluated.
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Titanium oxide and its properties in building materials
Rypák, Peter ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Theoretical part of thesis deals with conclusion of aquired informations about photocatalysis of titanium dioxide, its influence on properties of chosen building materials and its practic use in research of building materials with abitlity to decompose organic and anorganic matters. Experimental part deals with influence of quantity of titanium dioxide on mechanical strength of tested samples based on alkali activated slag and its ability to decompose organic colorant Rhodamine B
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Effect of admixtures on the properties of metakaolin geopolymer
Halasová, Kristýna ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Geopolymers are amorphous to semi-crystalline aluminosilicate polymers which are formed from inorganic polycondensation reaction of a solid aluminosilicate precursor with an alkaline sodium hydroxide or silicate. The resulting materials exhibit high durability, resistance to aggressive environments, high temperature resistance and many other properties that make them have received much attention in recent years, not only in construction. This thesis describes the influence of additives commonly used in concrete and mortar (water reducing, superplasticizer, air-entraining, foamer and defoamer, anti-shrinkage, stabilization) on the behavior of metakaolin in geopolymer fresh and hardened state. It describes metakaolin geopolymer effect on rheological properties of fresh mixtures, compressive strength and flexural strength after 28 days and a density in the fresh and hardened state.
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Rheological behaviour of alkali-activated aluminosilicates
Ševčík, Marek ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
The bachelor thesis is focused on rheological properties of alkali activated materials, the main focus is on rheological behavior of geopolymers. The theoretical part describes the most commonly used materials for the preparation of geopolymers. Further, described rheology in general and rheological properties are described, types of behavior of substances and differences between rheological properties of different types of aluminosilicates are explained. In the experimental part, mechanical properties of geopolymer pastes based on metakaolin and fly ash with different silicate moduli of alkaline activator – water glass were investigated. For these materials, rheometric measurements and rheological behavior were also performed.
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Effect of cellulose ethers on properties of hydraulic lime
Skoupil, Jakub ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
This diploma thesis deals with the study of the influence of cellulose ethers on the properties of hydraulic lime mortars. The availability and price of cellulose ethers in the industrial market is very favorable, but we can´t meet with studies using cellulose ethers in building materials, where lime is used as a binder. Cellulose ethers are commonly used as thickening agents in cement-based materials. The purpose of this diploma thesis is to review if cellulose ethers are appropriate for use in hydraulic lime mortars, either as water retention agents that contribute by water retention to better hydration of hydraulic binder components or to affect the properties of mortar in the fresh state. The theoretical part is dedicated to cellulose ethers, especially their production and how they influence the properties of building materials. In the practical part, the thesis deals with the influence of the dose of five different types of cellulose ethers on the properties of hydraulic lime. The properties in the fresh state and the physical-mechanical properties of mortars were monitored over time.
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Influence of heavy metal oxides on the formation and properties of Portland clinker
Kašpárková, Kateřina ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The Master’s thesis is focused on a study of the effect of increased content of heavy metals present in a raw meal on the formation and properties of prepared clinker and acquired cement. Main attention is devoted to changes on the physical, mechanical, microstructural and hydration properties. The theoretical part contains an overview of clinker minerals occurring in Portland cement including the possibility of incorporation of heavy metals into their structure and affecting the properities of the cement. In the experimental part, there is compared the effect of heavy metal oxides on the composition and hydration properties of portland clinker and physical-mechanical and microstructural properities of cement pastes prepared from this clinker.
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The ruins and the possibilities of their conservation
Pyreňová, Eliška ; Vyšvařil, Martin (referee) ; Rovnaníková, Pavla (advisor)
This bachelor´s thesis deals with a question of conservation of castle ruins. The theoretical part discusses generally building materials used in their construction, sort of material´s degradation and corrosion of materials, possibilities of ruin´s conservation by using suitable building materials, and processes in realization of historical property restoration. Work focuses on a history and conteporary condition of two historical buildings, the castle Cimburk in Czech republic and the castle Lietava in Slovakia. As a part of my work was collection and subsequent analysis of samples of historical mortars of these castle. Resulting response curves differential thermal analysis, RTG diffraction analysis and their mutual comparison.
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