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Study the abrasion resistance of concrete
Kolková, Kristína ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The thesis deals with the issues of concrete abrasion resistance and it consists of a theoretical research part and an experimental part. The types of abrasion affecting concrete construction and abrasion effect of flowing water-borne sand are described in the theoretical research part. A substantial part is dedicated to the impact of concrete properties and to each material of the concrete mixture on the abrasion resistance. The impact of addition of various types of fibers is inquired. The mixtures with the addition of 2 kg.m-3 and 4 kg.m-3 of basalt fibers and the addition of 1 kg.m-3 and 2 kg.m-3 of polypropylene fibers are designed in the experimental part. The mixtures are compared to a reference mixture without fibers. Density and consistency of fresh concrete settling at 5 minutes are determined in fresh condition. Density, compressive strength, tensile strength, watertight, concrete absorption and bending tensile strength are determined on hard concrete. The impact of the addition of fibers to the concrete abrasion resistance is inquired using the Bohm abrasion method and wheel abrasion method. A water jet is used as another method for testing abrasion resistance and for comparing the suitability of the used methods.
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Stabilization of the flooded sand pit near Hulín
Tomšej, Lukáš ; Svoboda, Ondřej (referee) ; Šlezingr, Miloslav (advisor)
The diploma thesis assesses the current state of the Hulín gravel and sand plant and pays attention to abrasions of severely damaged banks of the reservoir. With the help of the design of a suitable biotechnical stabilization, the receding of the shoreline in the section of interest will be prevented. The basis for the processing of appropriate bank stabilization proposals is the results achieved using a method of determining shore retreat. The individual developed variants of the bank remediation solution emphasize the use of vegetation support, especially suitable bank stands to ensure the stability of the banks and protection against abrasion.
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Stabilization of the flooded sand pit near Hulín
Patková, Aneta ; Pelikán,, Petr (referee) ; Šlezingr, Miloslav (advisor)
The aim of this bachelor thesis is to assess the current state of the bank damaged by abrasion of the flooded gravel and sand pit in Hulín with the subsequent proposal of suitable biotechnical or biological stabilization and hydrological calculations to determine the prognosis of the prognosis retreat of the coast. As part of the field survey, photo documentation of abrasive log cabins caused by wind waves and water level fluctuations was taken. Part of the work is also the proposal of a total of six stabilization measures, the construction of which should prevent or slow down the effects of abrasion.
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Study on wear of material in contact with MR fluid
Žáček, Jiří ; Vimmr, Jan (referee) ; Kubík, Michal (advisor)
This paper is focused on MR dampers and its critical parts in term of damper`s durability, which seems to be a piston-rod seals, and it should find an ideal material combination of seal and MR fluid for increasing the damper`s life. The tests were conducted in modified pin-on-flat configuration, which was supposed to be more suitable for laboratory testing. There was tested and compared a suitable material for seals, like PTFE, NBR, SBR of polyurethanes. The article is also focused on MR fluids and its contribution to seal`s wear. The impact of particle concentration, wear of MR fluid and effect of modification of MR fluid was tested. It showed up, that the best material for seal is H-PU95FDA. The effect of particle concentration is negligible on seal`s wear, while effect of modification and wear of MR fluids are significantly higher.
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Establishment of bank slope retreat forecast
Čuda, Ondřej ; Pelikán,, Petr (referee) ; Šlezingr, Miloslav (advisor)
The diploma thesis deals with the assessment of the condition of the bank area of the flooded gravel sand pit Hulín, the subsequent design of active anti-abrasion structures and the determination of the point of maximum retreat of the bank line. As part of the assessment, a personal field trip was carried out, during which, in agreement with the supervisor, a shore section was designated for the subsequent proposal of a stabilization measure and its photo documentation. From the data provided by the supervisor, the characteristics of the waves, the starting length of the wind, the level of the heel of the highest abrasive log house were calculated and the point of maximum retreat of the shoreline in the focused transverse profile of the solved section was determined graphically. Part of the diploma thesis is the design of a total of six active anti-abrasive structures, the construction of which will prevent further retreat of the shoreline and support the creation of a habitat for local animals.
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Development of abrasion-resistant concrete and testing methods
Procházka, David ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with concrete abrasion resistance against abrasion. The constructions of transport and water management structures are most stressed by the action of abrasion by means of travel of vehicles and flowing water. Abrasion reduces the durability of the structures. The prerequisites for achieving the best possible abrasion resistance are examined. Furthermore, test methods that are currently used worldwide. The experimental part deals with the influence of individual types of aggregates amphibolite (Želešice), fecal gravel sand (Žabčice) and basalt (Bílčice) on abrasion resistance. Furthermore, the dependence between the strength of the concrete and the hardness of the surface for abrasion resistance. Abrasion resistance testing was determined by concrete abrasion, abrasion resistance by the Böhm method and by water jet.
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Proposal to revitalize the banks of the flooded Hulín sandstones - section 2
Čuda, Ondřej ; Pelikán,, Petr (referee) ; Šlezingr, Miloslav (advisor)
The subject of this bachelor’s thesis is to prevent the retreat of the bank line by the proposal of suitable biotechnical stabilization of the banks of the flooded Hulín sandstones on the specified section. Shore abrasion is mainly caused by the starting wind, which results in the formation of waves that subsequently spread the banks. The result of the thesis is the processing of biotechnical stabilization proposals, which are intended to reduce or slow down the retreat of the bank lines.
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Measurement of wear in shock absorber with magnetorheological fluid
Žáček, Jiří ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with measurement of abrasivity of magnetorheological fluids and its effect on hydraulic shock absorber. The abrasion could be measured and evaluated by many ways. The pin on block measurement method has been selected for this test. The pin was moving on a steel block while the whole system was surrounded by magnetorheological fluid. According to results, the lifetime of magnetorheological shock absorber is 4 times shorter than classical damper. Results of this thesis could be helpful in damper construction or in development of new magnetorheological fluids.
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