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Properties of alkai-activated aluminosilicates subjected to high temperatures
Halasová, Kristýna ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Currently the concept of geopolymer or alkali activated aluminosilicate is very mentioned topic. Many studies concerning utilization of these materials have already been made, but if we want to use these materials in building industry in the future, further research will be needed. This thesis deals with the influence of high temperatures on alkali-activated slag, fly ash and metakaolin-based composites. The work compares mechanical and technological properties, microstructural changes and effect off iller on the geopolymer composites heated at 200–1200 °C. In conclusion, the individual properties are compared and application possibilities of these materials are evaluated.
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Solid Particle Emissions from AgroPellets Combustion
Svoboda, Marek ; Milčák, Pavel (referee) ; Lisý, Martin (advisor)
This thesis is divided into two parts. The first part deals with defining the main concepts, properties of biomass and pellets. Further, the procedures for measuring agropellets properties according to valid standards are mentioned. The following is a selection of the raw materials for the production of agropellet, with the determination of their properties. The theoretical part closes background research emissions from combustion and emission standards for a solid fuel boiler. The second part is an experimental one, which determines the formation of solid pollutants in combustion of four types of pellets made from alternative sources. Here are the graphs of the gaseous emissions of each of them. At last there will be a comparison of emissions agro pellets with more widespread wood pellets.
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Activation admixtures in concrete
Eger, Lukáš ; Hela, Vlastimil (referee) ; Hela, Rudolf (advisor)
The aim of my bachelor´s work is the summarization and focus on admixure concrete,and the active and inert admixure, which have some positive characteristies for fresh and hardened concrete. Theoretically, I tried to study the increase of their joining potential while this characteristic can be used by either chemici or mechnical way, their combination as well. I also Works on evaluetion of physically mechanical influence for fresh and hardened concrete that can up to 60 days old while the cement was partly substituted by admixure of different character.
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System for Exhausting of Combustion Gases over the Sintering Grate
Kratochvílová, Silvie ; Galas, Radovan (referee) ; Dvořáček, Jiří (advisor)
This bachelor thesis deals with solution for waste gases exhaustion system above the sinter grate. The first part is dedicated to the general treatise about sinter grate, its operations and individual modifications. Another part looks into issues covering placing of the cover above the sinter grate. Proposal of optimal solution of the waste gases exhaustion system is done in last part, where are described reasons, which lead to its choice.
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The development of grouting for additional sealing of embankment dams
Michalčíková, Magdaléna ; Klablena,, Petr (referee) ; Drochytka, Rostislav (advisor)
Seal of sand or gravel by chemical injection is known and used for a long time. Chemical grouting are however expensive and sometimes the use of cement does not lead to desire effects. So it is trying to find new materials and methodologies injection arrangement works. To achieve savings of chemical products are added to a mixture clay and cement. Clay-cement grouting mix are used not only in order that they are better quality, but also because in this way proposed mixtures have a tendency to penetrate better into incoherent sediments that need additional sealant of chemical injection. For further possible reductions of economic terms the mixture is trying to replace the classic clay. As a suitable substitute for classic clay is to a certain extent the use of secondary raw materials. Above all it is fly ash. As a part of my thesis I deal with the appropriateness use of these materials and examining their properties in the mixture. It was found that by using fly ash were improving consistency of the fresh mixture, reducing the amount of water-cement ratio and reduce shrinkage of the mixture. On the other hand, by using fly ash has been increasing decantation, permeability atc. In the next stage of my work was examined the influence of the quality of cement, lime and liquefaction in the mixture. The aim of thesis is to propose the optimal injection mixture for additional sealing earth dams.
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Magnetic classification of fly ashes and application of products
Červený, Ľuboš ; Švec, Jiří (referee) ; Šoukal, František (advisor)
Submitted bachelor thesis is dealing with problematics of magnetic separation of fly ash and utilization of the products of the separation in production of refractory ceramic materials. High temperature fly ash from power station Mělník was used in this thesis.Thesis evaluates results of magnetic separation at different setting of magnetic separator. It proves, that fraction of particles rich in iron as well as fraction depleted by this iron can be obtained by magnetic separation. In this thesis are presented results of volumetric weight, mineralogic element composition, measurments by heating microscope and results of particle size distribution of unseparated fly ash, but also its both separates. The thesis is focusing on possibilities of utilization as additive in refractory ceramic materials and comparison of their refractory properties. It evaluates results of characterisation of the products using XRD analysis and scanning electron microscopy.
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Asphalt recyclated material for base and subbase layers of pavements
Winterová, Karin ; Hýzl, Petr (referee) ; Stehlík, Dušan (advisor)
This bachelor thesis reviews the use of asphalt recyclated material and its application in the base and subbase layers of pavements. In addition to domestic knowledge, a foreign experience with the use of tested material and also covers currently used technologies for the processing of asphalt recyclates into the constructional layers of roads.is presented. Possibile application of asphalt recyclates in the unblemished and coated subbase layer of the road are verified in the practical part
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Development of structural concrete with power plant ash
Ťažký, Martin ; Sokol, Pavel (referee) ; Hela, Rudolf (advisor)
Worldwide production of concrete is increasing, what has a negative environmental load of cement production. That is due to effort in building construction, also concrete production, greater use of the secondary raw materials. Fly ash is the most commonly used secondary raw material. His used has a very good impact on the economy and ecology of production and positively affects on the properties of concrete in both the fresh and hardened state. The aim of this bachelor's thesis was to improve its use in concrete, using a minimum void fraction of dry mix cement-fly ash.
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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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