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Relationship between tensile strength and hardness of aluminium alloys
Růžička, Martin ; Jetela, Václav (referee) ; Klement, Josef (advisor)
This thesis deals with relationship between tensile strength and hardness of aluminium alloys. The introduction provides an overview of aluminum aloys and their properties. In the following section there is an analysis of the processing of aluminum alloys. A large part is devoted to the course of precipitation hardening. The second part of the thesis contains a practical part, which describes the methodology of measuring hardness and tensile strength. The measurement process is described below. At the end, the measured data are processed into various graphs and their results are evaluated.
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The study of the influence of the composition of the lightweight fiber concrete physical and mechanical properties
Šindelek, David ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with a study of light construction concrete with an addition of steel fibre which monitors its impact of the physical mechanical properties. The work is divided into two parts, theoretical and practical. The theoretical part is focused on characteristics and a design of light concrete within the class 35MPa and over with the density within the class of D1,8. Furthermore, it focuses on the increase of toughness of cementitious composites with the form of application of steel fibre in different doses and lengths. In the practical part, formulas of two strength classes 35/38 D 1,8 and 45/50 D1,8 were designed with the help of the steel fibre Krampeharex in doses of 25 and30 kg/m3, and where there were both its impact of the working diagram as well as the compressive strength monitored for the duration of twenty-eight days
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Properties of reinforcing glass-fiber geogrids in pavement structure
Maláník, Stanislav ; Šperka, Pavel (referee) ; Dašek, Ondřej (advisor)
Bachelor's thesis deals with the use of glass fiber reinforcement geogrids in road construction. Bachelor's thesis is focused on basic knowledge of reinforcing geosynthetics and on summary of existing regulations concerning the use of geogrids in roadway. The influence of the construction of the road layers on the change of the geogrid properties is evaluated by suitable tests. In particular, the effects of the impact of the movement of the construction technique on the geogrid and the effects of the compaction of the overlying layer on the geogrid properties were simulated in the laboratory.
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The verification of durability of surface layer by pull-off testing
Fujačková, Hedvika ; Komárková, Tereza (referee) ; Kocáb, Dalibor (advisor)
The theoretical part of this bachelor's thesis defines the basic properties, categorization, and use of the individual components of concrete and presents the properties of fresh and hardened concrete, especially the tensile strength. Furthermore, the thesis addresses the problem of durability assessment of concrete, which depends directly on the quality of the surface layer. The experimental part of the thesis focuses on executing of a pull-off test and examines the surface layer tensile strengths of various concrete mix designs. The thesis examines how the results of the measurements correspond with other published results.
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Study of FRP for concrete reinforcement
Blahová, Aneta ; Prokeš,, Jan (referee) ; Bodnárová, Lenka (advisor)
The diploma thesis aims to analyze bent FRP reinforcements. It describes the method of production of bent FRP reinforcement, examples of application of FRR reinforcement in structures and mentions aggressive influences influencing the durability of FRP reinforcement. Furthermore, an experiment is proposed to monitor changes in straight and bent FRP reinforcement stored in an aqueous environment at 20 °C and an alkaline environment at 20 °C and 40 °C. The output of the diploma thesis is the evaluation of changes in mechanical properties and durability. The condition of the FRP reinforcement is documented using optical and electron mocroscopy.
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Properties of reinforcing glass-fiber geogrids
Veselý, Petr ; Šperka, Pavel (referee) ; Dašek, Ondřej (advisor)
A proper road infrastructure is an essential part of today’s economy. Usage of roadways should be safe and its flow should be easy going. Primary net of roadways is already in place and attention shifts to its maintenance. Because of constantly increasing loads of heavy traffic, roadways are degrading at a faster pace, while there are still smaller time windows and less avialable resources for their reconstruction. That is why there has been rising demand for pavements that last longer and are able to carry higher weights. With respect to the rural roads it becomes obvious because of low amount of resources for their maintenance, that it is necessary to find an effective way to enhance pavements. From the foregoing it can be safe to say, that there is a clear need for reliable, durable and cost-effective technology of maintenance, such as the use of grids in asphalt pavements. This thesis deals with properties of geogrids made of glass fiber after its compaction as well as its effects on reduction or elimination of spreading of cracks in pavements.
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The effect of appication of fine organic fibers to cement composites
Kavka, Lukáš ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This bachelor thesis describes the effect of using fine organic fibers in cement composites. In the theoretical part of bachelor thesis a composite material was defined and his individual components were described. Then was created a research of information about organic fibers focused on natural fibers. The basic parameters of cellulosic fibers and polypropylene fibers, the effect on the properties of cement composites and their application in practice were described. In the practical part there were created a reference concrete and 3 types of concrete with the addition of various types of organic fibers. The influence of fiber addition on the properties of fresh and hardened concrete were investigated. Another task of practical part was monitored the resistance of cellulose fibers in acidic and alkaline media in which the tested fibers were deposited. The development of pH solutions was examined over time.
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Mechanical properties of glass fibers
Ševnina, Marija Vladimirovna ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis deals with the examination of mechanical properties of unsized glass fibers and commercially sized glass fibers. The main objective is to determine the tensile strength, modulus of elasticity, and ductility for the fibers depending on the surface modification. To determine these properties, fiber diameters were measured using an Olympus BX 50 optical microscope followed by a tensile test on the Universal Testing Machine, ZWICK / Z010 / TH2A.
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Analysis of the mechanical properties of plastic parts realized by 3D printing
Krejbychová, Adéla ; Benešovský, Marek (referee) ; Vosynek, Petr (advisor)
This bachelor thesis deals with the analysis of mechanical quantities of PET-G samples which were created by using 3D printing. The problem was solved experimentally. The samples were printed by using the FDM technology (Fused Deposition Modeling). Mechanical properties were measured by the tensile test and the measured quantities were further analyzed statistically. The influence of the pigment, the material manufacturer and the effect of setting the process parameters on the actual construction of the samples were investigated. On the basis of the carried out analyses it was discovered that the samples printed horizontally in the XY plane with a 45° / -45° fill angle from Devil Design had the best mechanical properties.
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Preparation and properties of Bioglass based foam materials
Nedbalová, Radka ; Hadraba, Hynek (referee) ; Dlouhý, Ivo (advisor)
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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