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Local tests of mechanical properties of materials
Wasserbauer, Jaromír ; Šoukal, František (referee) ; Zmrzlý, Martin (advisor)
This thesis deals with measurement of hardness and microhardness in relation to structure of homogeneous and heterogeneous materials. In the introduction basic theoretical background is commented, i.e. definitions, terminology, principles of measuring techniques for estimation of hardness, microhardness, tensile strength, compressive strength and bending strength. Follows a brief review of present research results focused on use of described principles in materials engineering. Then the experimental equipment and sample preparation is described. The crucial part of the thesis is summary of achieved results of original measurement and discussion of their relations to each other. Finally, the groundbreaking estimation is described, showing the correlation of chemical composition gradient and mechanical properties in interfacial zone of geopolymeric material.
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Results of Anorthite Creation in ceramic Body
Beránková, Karla ; Šveda,, Mikuláš (referee) ; Sokolář, Radomír (advisor)
Anorthite is crystalline phase in the ceramic body. Is acquired on burning a mixture of calcium ceramic raw material. This work deals with the influence on the resulting properties of anorthite ceramic body, especially flexural strength, porosity, shrinkage, thermal expansion coefficient. And the influence of different CaO sources on the properties. As a source of CaO was used calcium carbonate, calcium hydroxide and fluid fly ash.
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Modern Inorganic Building Materials Free of Portland Cement
Sadílek, Jakub ; Opravil, Tomáš (referee) ; Zmrzlý, Martin (advisor)
This bachelor’s thesis is focused on properties of modern construction inorganic ma-terials – geopolymeric concretes. In introductional part of work it is described basic theoretical background, as properties of binders, principles of setting and hardening. For preparation of geopolymer matrix was used secondary or waste materials of energetic and metallurgical industry – fly ashes and slags. In laboratory were prepared four com-positions of geopolymeric concretes combined from geopolymeric matrix with constant compostition and variable composition of aggregates. As aggregates these materials were used: three fractions of quartz sand, steel furnace slag and in one composition also crystals of mineral wollastonit. It was discovered that the use of steel furnace slag as aggregate in geopolymeric concrete has positive influence mainly to compressive strength, but the addition of wollastonite mineral do not evocate expectable increase of mechanical properties of samples.
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The influence of coatings on fracture behaviour of ledeburitic steel
Šafář, Martin ; Jurči,, Peter (referee) ; Hadraba, Hynek (advisor)
This work deals with tool steel Vanadis 6. It describes the preparation of samples for the three-point bending test, with which it examines the influence of surface roughness, the effect of nitriding, coating and duplex coatings on fracture behaviour of the steel. First, it examines bending strength and the total energy required to work of fracture. The work also includes mapping and measurement of surface roughness on different layers. This measurement is performed on a confocal microscope.
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Vplyv extrémneho umyvacieho procesu na pevnosť v ohybe lepeného spoja v listnatom dreve
Tuhý, Dušan
The diploma thesis is focused on the issue of the effect of the washing process on the bending strength of the glued joint in a special solid wood panel made of hardwood. The goal was to analyze currently available adhesives and types of joints in solid wood panels and to deal with the issue of the washing process and its influence. The selected glue was PVAc glue Rakoll ® GXL 4 and a butt joint, and then the changes in bending strength were compared on wood samples from beech, oak, ash and maple after thirty cycles of an intensive washing process using cleaning tablets and subsequent acclimatization of the samples. These were compared with samples that did not undergo the cleaning process.
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Innovative wood-based materials
Buriánek, Vlastimil ; Brožovský, Jiří (referee) ; Vaněrek, Jan (advisor)
This bachelor’s thesis deals with the issue of optimizing the modification process for plywood boards. Optimization consists mainly in evaluating different densification methods with different parameters of plasticization and stabilization. Psychical parameters (bulk density, swelling, water absorption) and strength parameters (bending strength, modulus of elasticity) of modified plates were chosen for the evaluation parameters. The practical part involved the verification of two thickening treatments on birch plywood.
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Additional reinforcement of wood elements
Janoušek, Radek ; Vejpustek,, Zdeněk (referee) ; Vaněrek, Jan (advisor)
This diploma thesis deals with the possibilities of additional reinforcement of wooden elements using different types of BFRP materials. In the practical part, an experiment of reinforcing plywood with external reinforcement using BFRP fabrics with different basis weights was performed. As part of the strength tests performed, the specimens were subjected to bending and shear stresses. To verify the bonding quality of the plywood, the bodies were exposed to the effect of elevated temperature and a delamination test was performed to determine the bonding quality of the plywood joints. The achieved values were evaluated and compared with the available literature.
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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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Stavba a vybrané vlastnosti dřeva paulownie
Přikryl, Vojtěch
This bachelor thesis deals with the structure and selected properties of wood paulownie. Test sample sets were manufactured from purchased joint boards tests were conducted to determine the following characteristics wood paulownie. The mechanical properties of the wood compressive strength 26.52 MPa and bend strength 39.70 MPa. From the physical the properties of wood were measured density at humidity 0 % 263.39 kg·m−3 and swelling in radial direction 2.78 %, in tangential directions 4.92 % and volumetric 8.75 %. Finaly and natural durability of wood was evaluated. The first part is described the theory of mechanical and physical properties of wood, in the second part the procedure for evaluating the measured values and the results compared with the first is described theoretical part.
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Možnosti nastavování překližek do větších formátů
Lempera, Martin
The bachelor´s work deals with problematics of longitudinal setting of plywood materials, for a purpose of comparing of mechanical features of particular glue mixtures at the connecting at chamfer. The first part of the work deals with characteristics, production and division of plywood boards. Follows the information about connecting and surface finish of plywood boards. The second part of the work contains methodology of carrying out tests and results of particular groups of samples according to glued materials. The main testing of samples was focused on modulus of rupture (MOR) and modulus of elasticity (MOE). Further performed tests were for a purpose of finding out of: moisture, density, durability of edges, their dampness and resistance of surfaces of plywood boards against abrasion.
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