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Vliv opracování a máčení na frekvenčně-rezonanční vlastnosti dřevěných nosníků reálných rozměrů
Janda, Martin
This paper examines the influence of processing on the acoustic properties of the wooden beams. Hewn beams and sawn beams were examined. Hewn beams were divided into three groups at two moisture content levels. Timber properties were determined by measuring the resonant frequencies. First part of the text is focused on the oscillatory motion and behavior of vibrating solids. Furthermore, there is a description of acoustic properties of wood and the possibility of using these properties when determining the mechanical properties. The next chapter is devoted to non-destructive testing of wood, which often uses acoustic methods.
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The Influence of Moisture of Lightweight Aggregate on the Concrete Properties
Pešek, Lukáš ; Lišovský, Martin (referee) ; Kocáb, Dalibor (advisor)
The bachelor thesis deals with the influence of moisture of lightweight aggregate on the concrete properties. In the experiment, test specimens from two different lightweight aggregate, and two different input moisture states of lightweight aggregate were tested. The tests were performed to determine the basic properties of lightweight concrete after 7, 28 and 90 days of maturing. Compressive strength, tensile splitting strength and depth of penetration of water under pressure were determined on cubic specimens. On the test prisms were performed tests to determine the flexural strength and dynamic modulus of elasticity. The results were processed and evaluated in tabular and graphical form to determine statistical data and formulate a conclusion.
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Methodology of historical bricks and masonry tests
Bartoň, Vojtěch ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
This diploma thesis is focused on methodology for sorting of solid fired bricks for reconstruction of historical buildings. The theorethical part of this thesis includes description of production technology of solid fired bricks and diagnostic methods. In practical part there are these methods aplied on the solid fired bricks, which are intended for reconstruction of the bridge in Sedlec. There are monitored changes in structure of solid fired bricks caused by repeated freezing and defrosting. This changes are monitored by resonant frequency method and ultasonic pulse method.
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Building survey and evaluating the state of construction
Balash, Alan ; Anton, Ondřej (referee) ; Heřmánková, Věra (advisor)
This diploma thesis is focused on building survey and evaluating of the state of the three-storey industrial hall. The diploma thesis consists of two parts - theoretical and practical. In the theoretical part is described a common procedure for evaluation of the state of existing structures, methods used in diagnostics (selected ones - more detailed), advantages and disadvantages of methods. In the practical part is carried out construction and technical survey of the industrial hall, the concrete strength evaluation and verification of presence and type of reinforcement. At the end of the work - evaluation of objects.
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The Use of the Ultrasonic Pulse Velocity Method for the In-situ Estimation of the Quality of Concrete
Sopúch, Martin ; Cikrle, Petr (referee) ; Kocáb, Dalibor (advisor)
The primary focus of this bachelor thesis is examination of concrete properties, principally with non-destructive methods. The ultrasonic apparatus Pundit PL-200 made by Proceq Company was used for the most of non-destructive examinations of the concrete. This paper is mainly focusing on determination of a modulus of elasticity. Measuring of the properties took place in the laboratory with use of probationary entities of 100 x 100 x 400 mm and in site on concrete block situated at BUT FCE campus. The probationary entities including twists from measured block were after non-destructive examining tested in the wring to secure more accurate results. The target of the research paper, firstly, was to attest options for determination of dynamic value. Secondly, with use of decreasing coefficient determine static values of elasticity modulus on the concrete that was built-in in a construction and, consequently, test practical usage possibilities of the modern apparatus Pundit PL-200.
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Diagnostics and assessment of prefabricated reinforced concrete structures
Kocuba, Robert ; Láník, Jaromír (referee) ; Cikrle, Petr (advisor)
This thesis deals with inspection and constructionally technical research of reinforced concrete prefabricated construction from the second half of 20th century. In theoretical part, the research of literature, documents and valid standards is performed, with a focus on production and construction of prefabricated elements and also on the metodology of research. In practical part, the detection of reinforcement of individual elements of the construction and concrete properties is performed. The result of this work is the assessment of the state of the construction, static calculation of the ceiling panel and idea proposal for eventual reconstruction.
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The Modulus of Elasticity of Air-Entrained and Non-Air-Entrained Concrete
Tichý, Aleš ; Misák, Petr (referee) ; Kocáb, Dalibor (advisor)
The bachelor thesis deals with the verification of the degree of influence of the air-entraining admixture on the modulus of elasticity of concrete. The experiment was carried out for these purposes. The values of static and dynamic modulus of elasticity were determined on drilled cores from concrete blocks of different mixtures. The magnitudes of dynamic modulus of elasticity were determined by using an ultrasonic pulse velocity method and a resonance method. The results are summarized in tabular and graphical form.
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