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Numerical support for description of behavior of cement based composite during fatigue test
Holušová, Táňa ; Padevět,, Pavel (referee) ; PhD, Ladislav Řoutil, (referee) ; Seitl, Stanislav (advisor)
The presented dissertation thesis is focused on analysis of alternative test method for determination of mechanical parameters of cement based composites. A disk shaped specimen with diameter 150 mm, thickness 60 mm was analysed and its modification for use on compact tension test (CT). Such a test is hereinafter referred to as modified compact tension (shortly MCT or MDCT)). This test configuration was chosen for testing the static and fatigue properties of cement based composites precisely because of its traditional use for fatigue testing of metallic materials. Specimens with a different cross-sections can also be used for MCT, but the work is exclusively focused on circular specimen, for example because it could be easily cut from drill core taken directly from the existing structure, on which the properties are more relevant to the age of the used concrete of the controlled structure. The modified compact tension test was firstly calibrated by numerical simulations involved the tuning of the shape of the numerical model and used material models of concrete and steel. Then the laboratory testing of modified compact tension on several levels were performed. The adequacy of the numerical model was verified against the pilot laboratory testing of the MCT test. Furthermore, the comparison of the modified compact tension test and its suitability for determining of fracture mechanical parameters of cement based composites with the three point bending test, which is the standardized test configuration for these purposes was performed. Another laboratory testing was focused of determining of fracture mechanical parameters of concrete mixture classified in strength class C30/37 and the pilot study of fatigue parameters of the same strength class of the concrete mix. The work was also presented numerical simulations of the push-out test, focused on the connection of concrete and steel with epoxy adhesive.
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Reinforcement concrete column strengthening via steel bandage
Stloukal, Štěpán ; Laníková, Ivana (referee) ; Šimůnek, Petr (advisor)
The steel bandage is an economical and effective widely used method for strengthening RC columns. Diploma thesis reviews most common design proposals for the types of the bandage with directly loaded and not directly loaded steel angles. This work also includes a comparison of the different constitutive laws for confined concrete. In order to simulate real behaviour of strengthened structure the numerical analysis has been carried out using non-linear software ATENA. According to the European standards and adopted hypotheses the simplified analytical model has been derived to be able to calculate load-bearing capacity of a strengthened column under normal force and bending moment. The proposed model considers the contribution in confinement pressure caused by steel bandage and the contribution of directly loaded angles. In addition, the direct application on real frame structure has been performed.
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Numerical support for description of behavior of cement based composite during fatigue test
Holušová, Táňa ; Padevět,, Pavel (referee) ; PhD, Ladislav Řoutil, (referee) ; Seitl, Stanislav (advisor)
The presented dissertation thesis is focused on analysis of alternative test method for determination of mechanical parameters of cement based composites. A disk shaped specimen with diameter 150 mm, thickness 60 mm was analysed and its modification for use on compact tension test (CT). Such a test is hereinafter referred to as modified compact tension (shortly MCT or MDCT)). This test configuration was chosen for testing the static and fatigue properties of cement based composites precisely because of its traditional use for fatigue testing of metallic materials. Specimens with a different cross-sections can also be used for MCT, but the work is exclusively focused on circular specimen, for example because it could be easily cut from drill core taken directly from the existing structure, on which the properties are more relevant to the age of the used concrete of the controlled structure. The modified compact tension test was firstly calibrated by numerical simulations involved the tuning of the shape of the numerical model and used material models of concrete and steel. Then the laboratory testing of modified compact tension on several levels were performed. The adequacy of the numerical model was verified against the pilot laboratory testing of the MCT test. Furthermore, the comparison of the modified compact tension test and its suitability for determining of fracture mechanical parameters of cement based composites with the three point bending test, which is the standardized test configuration for these purposes was performed. Another laboratory testing was focused of determining of fracture mechanical parameters of concrete mixture classified in strength class C30/37 and the pilot study of fatigue parameters of the same strength class of the concrete mix. The work was also presented numerical simulations of the push-out test, focused on the connection of concrete and steel with epoxy adhesive.
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Reinforcement concrete column strengthening via steel bandage
Stloukal, Štěpán ; Laníková, Ivana (referee) ; Šimůnek, Petr (advisor)
The steel bandage is an economical and effective widely used method for strengthening RC columns. Diploma thesis reviews most common design proposals for the types of the bandage with directly loaded and not directly loaded steel angles. This work also includes a comparison of the different constitutive laws for confined concrete. In order to simulate real behaviour of strengthened structure the numerical analysis has been carried out using non-linear software ATENA. According to the European standards and adopted hypotheses the simplified analytical model has been derived to be able to calculate load-bearing capacity of a strengthened column under normal force and bending moment. The proposed model considers the contribution in confinement pressure caused by steel bandage and the contribution of directly loaded angles. In addition, the direct application on real frame structure has been performed.
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