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Influence of transmission method on the results of measurement of refractory blocks by ultrasonic pulse method
Pospíšil, Dušan ; Dufka, Amos (referee) ; Brožovský, Jiří (advisor)
Ultrasonic pulse method is a non-destructive method, which is used in the construction industry to evaluate individual parameters of building structures. The aim of the thesis was to create the prerequisites for determining the rate of ultrasonic pulse propagation on refractory silica fittings and quartz glass fittings. Selected factors influencing the speed of ultrasonic pulse propagation in the tested samples were studied, namely the influence of the sounding direction, the influence of the natural frequency of the probes and the influence of the acoustic coupling material on the ultrasonic pulse method.
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New opportunities for the use of concrete structures sustainability assessment tools for a forensic engineering
Hrabová, Kristýna ; Kuda,, František (referee) ; Prostějovská,, Zita (referee) ; Vymazal, Tomáš (advisor)
In recent years, the European Union has been working to revise its climate, energy, and transport legislation to align existing legislation with the goals set for 2030 and 2050. These ambitions are closely related to the principles of sustainability. A growing population places increasing demands on the environment. Thus, improving living standards without damaging the environment is becoming a global challenge. The construction industry is an important segment of the world economy and contributes to environmental pollution. The concrete industry can also be counted among the main producers of CO2 emissions. The future of concrete construction design will be linked to new but also ongoing transformations of our society. The rapidity, speed, and frequency of the changes that are being implemented will also create a new urgency for knowledge and methodology in this field, whether for concrete producers, designers, or forensic experts. The focus of this thesis is the need to respond to new requirements in the field of concrete structures. In June 2016, the fib board approved activities to start working on the development of an updated fib Model Code 2020 (MC2020). This Model Code 2020 will form the source of new versions of the relevant Eurocodes and ISO standards, with sustainability as a fundamental requirement. Therefore, the design of a structure will now have to take into account not only durability considerations but also performance and overall environmental impact. Therefore, the dissertation focuses on the analysis of new trends in concrete structures to categorize the areas of change that may occur. The thesis deepens understanding of the areas of change as well as the methods of evaluation of building materials and concrete structures. Based on the identified shortcomings of the methods to assess the sustainability of materials, a sustainability indicator for CSB has been proposed. The changes brought about by the new fib Model Code 2020, whether in terms of performance-based design, use of recycled materials, or optimization of structures, may lead to defects and failures in building structures and new types of legal dispute for which there are no algorithms for resolution. In this paper, modern devices used for defectoscopy of defects and failure of concrete structures are also described.
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EVALUATION OF MASONRY BUILDINGS STATIC SECURING EFFECTIVENESS
Ledvoňová, Monika ; Šulák, Pavel (referee) ; Šulák,, Pavel (referee) ; Pospíšil,, Pavel (referee) ; Cikrle, Petr (advisor)
The theses looks into the evaluation of the efficiency of statical support of masonry buildings based on the measurements of changes to the crack width of the building. Monitoring of building is one of the main tools for their evaluation, in addition to the initial inspection and survey. In this way, monitoring is given in standards, for example in ČSN ISO 13 822 Bases for design of structures – Assessment of existing structures [1]. The first theoretical part is focused on defects and failures of brick masonry and methods of its monitoring, especially the measurement of displacements in cracks in masonry buildings with a special focus on the use of Hollan crack measurement gauge. The research part listed chronologically alternatives of structural support, both implemented during the construction works or afterwards. The comprehensive chapter then describes in detail wrought iron rods, this work deals with the testing of these rods in its laboratory part. The entire issue of practical part closely focuses on masonry estates built between the 1850s and 1950s and it is divided into two separate chapters. One part deals with laboratory tests of wrought iron rods, as one of the main reinforcing elements of historic masonry buildings that belong to the period in question. These elements were tested non-destructively (tests using a hand-held hardness tester and a hand-held X-ray analyzer) and subsequently also subjected to destructive testing, in which tensile tests of these rods were performed, including their joints. The subsequent practical part is focused on the complex monitoring of a selected brick building, which was damaged by bordering construction activities, specifically the construction of a multi-storey residence in its immediate vicinity. The results of this measurement enabled the design of a methodology for monitoring multi-storey masonry buildings, which completes and concludes the whole topic.
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Acoustic emission signal classification at cyclic loading of parts
Stein, Pavel ; Mazůrek, Ivan (referee) ; Mazal, Pavel (advisor)
This master’s thesis is concerned analysis of signal of acoustic emission. The analysis is based on data of bearing material and real bearings testing, tested in the Axmat stands. The data was run by software Matlab and Python. Below I created plan for identification of damage stage depending on particular AE events. The results are put into diagram. Finally I’m trying to develop the new possibilities of using acoustic emission into practice on the real machines. There could be earlier prediction of a defect of monitored bearings compared to vibrating diagnostic used until now.
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Diagnostics of selected bridge structure
Jedlička, Lukáš ; Láník, Jaromír (referee) ; Žítt, Petr (advisor)
This thesis deals with building survey of bridge register number 43-011 located near Česká. The part of thesis is literary reaserch dealing with system of management and cotrol of road bridges, precast bridge contructions made with DS-C type girgers and about general diagnostical methods. The practical section contains of in situ diagnostical survey and bridge inspection, laboratory evaluation and comparision, load bearing capacity calculation and suggestion of potencional technical precautions.
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Modern trends in radiographic procedures and methods in defectoscopy
Skřivánková, Vendula ; Vlašic, František (referee) ; Juliš, Martin (advisor)
Presented thesis deals with modern trends and techniques in radiographic methods of crack detection which are recently used in engineering practice. In the first part, conventional (analogue) radiography principles based on creating a visible image of tested object to radiographic film are discussed. The next part is aimed to the digital radiography and radioscopy. To digitize existing X-ray film images, application of storage phosphor plates (CR), flat panels (DR) and computed tomography (CT).
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Optimization of manufacturing of iron castings to reduce the quantity of defects
Blaha, Marek ; Brázda, Zdeněk (referee) ; Juliš, Martin (advisor)
The presented diploma thesis is focused on defects of castings as well as optimization of production with the aim of reducing the number of defective products. The theoretical part is focused on basic information about cast iron and its production, structure and mechanical properties. Another part of this thesis describes the defects of castings and options for non-destructive testing of cast iron castings. In the experimental part are analyzed three sorts of defective casting. Castings for testing were provided by JMA s.r.o. foundry. The summary contains tests results and proposals for optimization of production.
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Diagnostics and assessment of the bridge structure
Fadrný, Michal ; Heřmánková, Věra (referee) ; Kocáb, Dalibor (advisor)
This diploma thesis targets on diagnostics and assessment of bridge structure Most Kaštanová přes Svitavu, reg. number 380-001. Concrete material characteristics have been assessed in laboratory, after visual inspection, diagnostical testing and sample core drilling were made. Findings from laboratory tests are summarized in the conclusion of the thesis. It focuses on an evaluation of current bridge condition and presents various options that will help polong lifetime of the bridge.
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Preliminary survey and assessment the building before renovation
Bartoň, Vojtěch ; Stehlík, Michal (referee) ; Cikrle, Petr (advisor)
This bachelor thesis deals with the construction and technical survey of a masonry building with cast iron columns. Construction-technical survey was carried out, due to the planned conversion of the building into a apartment building with public services. The thesis contains description of construction and technological survey and diagnostic methods, which includes evaluation of essential characteristics of masonry structures and cast iron columns. The practical part contains processing of diagnostic survey. Its result is determination of material and geometric characteristics of the structure.
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Modern methods in nondestructive testing of materials using ultrasound
Šimeček, Radek ; Stránský, Lubomír (referee) ; Juliš, Martin (advisor)
Theme of this bachelor thesis is nondestructive testing of materials by modern ultrasound methods. In the first part are mentioned defects of mechanical components, which can be detected by ultrasound. This is followed by a description of conventional ultrasound technique, including a list of the major disadvantages and limits. In the second part are analyzed the modern ultrasonic methods TOFD and Phased Array. It describes not only the principle of these techniques, but there are also provided practical examples of their application.
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