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Experimentální ověření vlivu typu vláken na chování vláknobetonů / Experimental Investigation of the Influence of the Type of Fibres on the Behaviour of Fibre ConcreteHanuš, Petr January 2019 (has links)
This diploma thesis deals with the comparison of different properties of fibre-reinforced concrete according to the type of fibres. The main monitored property is flexural strength, tested on prisms with a cross section of 150x150 mm and a length of 600 mm. Four concretes of natural aggregate and four concrete of lightweight aggregate were prepared for the experiment. There were 2 reference concrete and 6 fibre-reinforced concrete. Three types of fibres were used: steel, polypropylene and glass. More than 2500 kg of concrete was produced. The aim of the thesis is to assess the influence of fibres on the flexural strength and other characteristics of fibre-reinforced concrete.
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Lokální zkoušky mechanických vlastností materiálů / Local tests of mechanical properties of materialsWasserbauer, Jaromír January 2009 (has links)
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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Návrh a realizace zařízení pro měření síly v tahu u SMD / Design and realization of the pull strength measuring device for SMDValíček, Jan January 2013 (has links)
This thesis deals with the design and implementation of a device for measuring pull strength by surface mounted devices (SMD). It analyzes the theory of pull strength testing of solder joints with emphasis on standard IEC 62137-1-3 and describes the selection of components utilized to create mechanical construction and electrical parts. These electronic parts made or innovated in this work were control system based on microcontroler Atmega164P, power circuit for stepper motor and communication of measure equipment TEST 321 with PC. The whole design is complemented by simulation of mechanical stress to the critical components using ANSYS. The conclusion summarizes the most important parameters of this equipment.
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Vývoj a zkoušení vysokohodnotných betonů pro subtilní konstrukce / Development and testing of high performance concrete for subtle structuresMyšičková, Lucie January 2014 (has links)
Thesis describes properties of HPC compared to concretes of normal and high strength. It further describes the input materials and the procedure for designing the composition of the mixture. It gives examples of already completed structures made of HPC. The experimental part describes the optimization of concrete mix and production of specimens. In the end results of testing the properties of the developed mixes from tests of dynamic and static modulus of elasticity, compressive strength and tensile strength by bending are described.
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Vliv rozptýlené výztuže na fyzikálně-mechanické parametry výsledného kompozitu / Influence of dispersed reinforcement on the physico-mechanical properties of the resulting compositeLáník, Jaromír Unknown Date (has links)
The dissertation is focused on the issue of implementation and evaluation of the laboratory tests fiber reinforced concrete. The issue of steel fiber is solved in terms of their physico-mechanical parameters, which are an important part of their design and reliable operation in the product design. The experimental part of the thesis is focused on laboratory tests of steel fiber of different strength classes and different weight benefits of steel fibers, the default reference mixture of plain concrete are certified mixtures commonly used as structural concrete in construction. The evaluation of the testing of samples produced steel fiber is made by three selected recommending regulations for the design and testing of structural steel fiber. In conclusion, the individual obtained experimental results are compared.
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Vliv modifikace na pevnost lepení bukuŠmíd, Pavel January 2019 (has links)
This diploma thesis is focused on the influence of thermal modification on the strength of bonded joint in tension according to ČSN EN 205. For the purpose of this work was used beech wood. The thermal modification of the test samples was performed at temperatures of 160 °C, 180 °C and 200 °C. The selected bond strength adhesives were melamine-urea formaldehyde adhesives (MUF), phenol-resorcinol formaldehyde adhesives (PRF) and one-component polyurethane adhesives (PUR). In addition to the thermal modification the effect of plasma modification on bond strength is also determined. The test lamellas were plasma treated (DCSBD) prior to gluing and pressing. The result is the determination of the tensile strength of the bonded joint in all the above-mentioned modifications and comparation of the results.
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Eliminace negativních vlastností betonů vyvolaných použitím recyklovaného kameniva pomocí čedičových vláken / ELIMINATION OF NEGATIVE PROPERTIES OF CONCRETE INDUCED BY THE USE OF RECYCLED AGGREGATES USING BASALT FIBERSFittl, David January 2022 (has links)
The thesis summarises information about recycled aggregates and basalt fibres, their interaction in composite material such as concrete. It focuses on the potential deficiencies and properties of concrete due to the use of recycled aggregates and on the possibilities of their subsequent elimination of their negative impact by the use of basalt fibres. It characterizes individual raw materials and their interaction in concrete. It includes verification of the properties of the individual sub-components and the resulting concrete itself. An assessment is made of the impact of the use of recycled aggregates on the properties of concrete (compresive strength, static modulus of elasticity, residual flexure tensile strength and others). The thesis discusses the question of whether the same or similar mechanical properties of concrete can be achieved with natural and recycled aggregates using basalt reinforcing fibres. The work provides for the possibility of settlement the values of these concrete parameters by using basalt fibres as a dispersed reinforcement in concrete. The recycled aggregates come from concrete company JARO AS in the north of Norway, where this work was conducted with the financial support from Erasmus+ at The Arctic University of Norway - campus Narvik.
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Příprava a vlastnosti pěnových materiálů na bázi Bioskla / Preparation and properties of Bioglass based foam materialsNedbalová, Radka January 2014 (has links)
The work deals with the preparation and mechanical properties of coated Bioglass® 45S5 based foam materials with open porosity. The samples have been fabricated applying the replication method with use of polyurethane foam. Furthermore, these samples were coated in order to increase the strength characteristics and crack resistance. Polyvinylalcohol and PVA with cellulose microfibrils have been used as coating. Besides microstructural parameters of investigated materials using the SEM images strength characteristics in compression and in tension were also quantified.
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Analýza a řízení provozu nové výroby v podniku / Analysis and operation management of a new production in companyMIKULÁŠKOVÁ, Petra January 2013 (has links)
The thesis analyses manufacturing process of wooden handles as a component part of bench chisels. The introductory part summarizes basic theoretical knowledge regarding production process, production preparation, production management and cycle, as well as layout of the workplace. The main part focuses on analysis of wooden handle production with the use of in-dustrial engineering methodology. Analysis of material flow, workplace arrangement, methodics 5S, low-cost automation, pull system, Kanban and utilization of waste were carried out in order to find improvement possibilities in the wooden handles production. Solutions for better production efficiency and increase of production capacity are proposed from the findings of this thesis.
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Vliv mnohonásobného zatěžování na vybrané parametry lehkého betonu / Influence of multiple cyclic loading on the selected parameters of lightweight concreteAlexa, Martin January 2018 (has links)
The diploma thesis deals with the observation of the values of selected parameters (especially the static modulus of elasticity) of light-weight concrete in compression before and after multiple cyclic loading. The deformation of test specimens during multiple cyclic loading were measured with resistive strain gauges. Test specimens (cylinders with a diameter of 150 mm and height of a 300 mm) were cyclically loaded and up to 4 500 loading cycles were performed. The aim of this thesis is assessment changes in the values of static modulus of elasticity depending on the number of loading cycles.
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