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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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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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Plasticizers replacing lime in cement-lime mortars
Kajsrlík, Jan ; Bayer, Patrik (referee) ; Vyšvařil, Martin (advisor)
This bachelor thesis deals with the possibility of replacing lime in lime-cement plaster mortars. Considering commercially sold products, it explores the ways of replacing lime qualities by organic materials. Their influence on density, beam test and compression strength are researched; absorption capacity, frost resistance, capillary absorption coefficient are also assessed. Finally the organic materials are compared with the qualities of the lime-cement mortar
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Effect of the composition of alkaline activator on the properties of hybrid cements
Šimko, Lukáš ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Building industry, especially production of Portland cement is the most ecologically and energetically demanding sector. Therefore, there is an effort of using waste products of energy industry as a (partial) substitution of conventional building materials. This bachelor thesis deals with the possibility of using the power station fly ash as a major part of mixtures with Portland cement, and therefore as a hybrid cement. In the experimental part, the influence of silicate module on the characteristics of mortars, whose binder is composed of 20% of Portland cement and 80% of fly ash from Dětmarovice power station, is examined. It further deals with influence of composition of alkaline activator on its characteristics. Its properties are examined in terms of porosity, strength and microstructure. Size and distribution of pores are examined by means of mercury intrusion porosimetry and evaluation of microstructure is based on scanning electron microscopy.
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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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Effect of water-lime ratio on the properties of lime mortars.
Kurfürstová, Nela ; Vyšvařil, Martin (referee) ; Rovnaníková, Pavla (advisor)
Diploma thesis gives a brief description of the traditional technology of preparation of lime mortars for restoration of historical buildings. The theoretical part is focused on the preparation of lime mortars traditional methods, using appropriate materials for making and influence amount of water. Attention is also paid to the events that take place in the setting and hardening of lime mortar. In the experimental part of the research was conducted, which aimed to assess the influence of water-cement ratio and mixing ratio (binder to filler) on the properties of lime mortars. At various times were measured mechanical properties, density, shrinkage, frost resistance and porosity. The mortar was also carried out thermal analysis and found to contain calcium carbonate. Acquired knowledge could help in the reconstruction of historical buildings.
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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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Lime Mortars Modified by Fine Ground Brick Body
Šmerdová, Ludmila ; Vyšvařil, Martin (referee) ; Rovnaníková, Pavla (advisor)
Natural pozzolanic materials played an important role in Ancient architecture. In the last decades and nowadays it is artifical pozzolan which especially finds its use as an additive to mortar and concrete to improve some, especially the mechanical properties. This master thesis deals with study of pozzolan type of fine brick powder which is a by-product of the production of calibrated bricks. Along with studying pozzolanic activity of brick powder, lime mortar with different proportions of brick powder as an additive or replacement of lime dust are investigated. What is observed is its impact on the consistency of these mortar, water absorption, strength in time or fracture-mechanical parameters of mortar. The results may indicate the possible potential use of this source of pozzolanic admixture in lime mortar and plaster which are nowadays mainly used for the restoration of facades of historic buildings.
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Application of foaming agents for the production of lightweight materials
Kramná, Adéla ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Use of lightweight building materials came to forefront in recent decades. The most commonly used materials are aerated and foam concrete but also other materials such as foamed geopolymer have been introduced. This study examines foaming methods of various lightweight building materials which are analysed and evaluated in terms of properties in hardened state. An effect of foaming agent on the structure of the material and its porosity was examined by image analysis using an optical microscope.
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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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