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The preparation of cellular concrete for insulating purposes
Koutný, Ondřej ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
In these days of economic crisis subsiding, in the civil engineering the attention is pointed especially to the systems, which effectively reduce energy and decrease costs associated with using of residential or industrial premises. Especially the heat-insulating systems are mentioned, because of their characteristics and construction which will be applied economical solutions. It is possible to use the materials based on aerated concrete which excel within construction materials due to its heat-insulating properties. The use of this material for clearly heat-insulations seems to be fully-fledged alternative to standard heat-insulating systems also due to combination of nature character and sufficient strength. This work deals with possibility of preparation non-bearing, heat-insulating material based on autoclaved aerated concrete with volume weight under 200 kg/m3.
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The determination of the composition of refractory material by X-ray fluorescence.
Janča, Martin ; Šilerová, Iva (referee) ; Šiler, Pavel (advisor)
The goal of this Bachelor thesis is to find the right way for the analysis of the refractory materials that would be accurate and could be repeated. The ideal method that would help us achieve our goal seems to be the fluorescent spectrometric analysis. This method is used very often in case of instant control of the quality of production in the cement and other heavy industry enterprises. Using the fluorescent spectrometric analysis comes with one issue, which is the presence of many distorting interferences. From this particular reason it is necessary to identify these interferences and then find the ideal solution of their elimination. Because of the possibility to have the sample in any shape or form at the x-ray florescent spectrometer it was necessary to choose the right method of preparing the sample for the analysis as well as choose the right parameter for the measuring itself and for the elimination of undesirable interferences.
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The optimalization of clay building components
Melichar, Jindřich ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
Clay building components are nowadays one of the most used building materials in the world. Except easy availability and processability clay building components have also heat storage function. This master´s thesis will be considering possibilities of improving thermal and mechanic properties of these materils by additing suitable reinforcements.
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Composite cements with heat-convertible polymer - preparation and parameters
Surman, František ; Šiler, Pavel (referee) ; Havlica, Jaromír (advisor)
This bachelor’s thesis deals with the preparation and study of composite material based on thermosetting polymer (phenol resin) and inorganic binder (high alumina cement). Very high mechanical properties, considerable stability to moisture and heat are specific properties of this polymer-cement composite. The special preparation means high-shear mixing, which depends resultant properties of composite to a considerable extent. Theoretical part reveals the reason of high achievements, which are typical for this polymer-cement composite but not for other type of inorganic binder used in this composite. This part furthermore studies chemical and physical processes, which occurs in composite mixture during processing and hardening, environmental durability and general applications of polymer modified cements. Practical part includes the laboratory preparation of phenol resin and the study of flexural strength of composite according to resin content in composite mixture. The flexural strength was measured by universal test machine Zwick Z010. Microstructure of material was observed by optical microscopy.
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The effect of fly ash on the properties of cement mortars.
Bayer, Petr ; Brandštetr, Jiří (referee) ; Šiler, Pavel (advisor)
The consumption of the cement for construction industries is increased every year. That is associated with greenhouse gas emissions, especially carbon dioxide CO2. Reduction of greenshouse gas emissions can be achieved by maximisation of the use of cementitious and pozzolanic by-products. As by-product could be used blast furnace slag and fly ash. My bachelor’s thesis is focused on the possibility of the partical replacement of the cement by fly ash. High temperature and fluidized fly ashes will be tested. The goal is to examine the behavior of the cement mortars in compensation of 10, 20, 40 and 60 % by weight of cement by fly ash. The compressive and flexural strength and isoperibolic calorimetry measurement were performed.
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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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Possibilities of utilization of solid residues from fluidized bed combustion for preparation of composite Portland cements
Beranová, Denisa ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
The bachelor thesis deals with possibilities of utilization of solid residues from fluidized bed combustion of coal, bed and filter ash, to be used in the production of composite Portland cements. 6 ash types were investigated, of which 3 were bed ash (finely ground) and 3 were filter ash colected from Ledvice, Tisová and Poříčí K8 power plants. The chemical composition of the ash collected was determined and the progress of a hydration reaction monitored, and then samples mixed with Portland clinker were prepared. Their respective compressive strength and flexural strength were then analysed and observations made on the hydration and composition of products of the hydration reaction. Finally the results of selected mixtures were verified with prepared standardized mortars.
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The study of adhesion of glued balistic composites on the dependence of materials used.
Dobiáš, Jiří ; Másilko, Jiří (referee) ; Šiler, Pavel (advisor)
The aim of this work was to investigate the properties of bonded ballistic materialsBalistic composites are mainly glued to reduce weight while keeping their protective properties. On this basis, the materials used were ballistic steel, ceramics, rubber kevlar, non-gummed kevlar, Dyneema and fiberglass. For bonding used were a one-component adhesive Collano 36.104 and two-component adhesive Biresin U1305. The strength of the joint was measured in shear at tensile loads. From these results, deformation energy was further calculated.
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Influence of zinc on mechanical properties of cement composites
Štarha, Tomáš ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
The theme of this bachelor thesis is to monitor the effect of zinc on mechanical properties of portland cement. Zinc was tested in the form of zinc oxide. Three acceleration additives were added, calcium oxide, formic acid and calcium formate in various proportions. Furthermore, the mechanical properties of all these mixtures were monitored by measuring flexural strength and compressive strength at 7 and 28 days after mixing and mixtures were analyzed by XRD and DTA. Also using isoperibolic calorimetry, the hydration of CEM 42.5 R cement zinc oxide was monitored.
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The optimization of melting as a decomposition process for material analysis.
Ptáček, Martin ; Koplík, Jan (referee) ; Šiler, Pavel (advisor)
Fusion is the process in which the sample particles are dissolved in the flux. This is used for the decomposition of substances which under normal conditions do not decompose in acid. For example, silicon, which is a substantial part of cement, is not degraded under standard conditions, so it is fused. Fusion may be in solution or in a pearl. Solution fusing is used for ICP-OES rather than XRF pearls. In addition to the pearl, XRF can also be measured in powder, but it is less accurate. This bachelor thesis deals with decomposition of standards and comparison of measured values with certified values. In the course of the work, samples of the standards were decomposed using several types of fluxes, measured at ICP-OES. The same standards were measured using XRF in the form of pearls. In addition to these two methods, elemental analysis of sulfur content was also performed. These methods were finally compared. From the measured data we can say that the best results are achieved with the ICP-OES method.
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