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Possibilities of dispersed reinforcement for lightweight concrete
Novotná, Aneta ; Žítt, Petr (referee) ; Láník, Jaromír (advisor)
Master´s thesis deals with some problems associated with utilisation of lightweight concrete from the porous aggregates in the load – carrying structures. The thesis focuses on the possibilities of the increase of the cement composites toughness using dispersed reinforcement. Lightweight concretes were reinforced with a combination of different lengths of polypropylene fibers Forta Ferro. There were used polypropylene fibers of three lengths 19, 38, 54 mm. The thesis is divided into theoretical, experimental and static part.
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Adhesion Strength and Fracture Morphology between FRC Root Canal Post and Particulate Filled Composite Core
Kročová, Blanka ; Pavelka,, Vladimír (referee) ; Poláček, Petr (advisor)
This bachelor thesis examines the influence of composition and structure of the dental pin on its mechanical properties. It deals with the adhesion strength and fracture morphology of adhesive joints between composite, fiber stiffened root pin (FRC) and a core of particle composite. There is observed adhesive strength dependence on the diameter of the pin FRC, the fiber content of the pin and the use of the composite particle in which the pin is embedded. Shear, adhesive joint strength was measured using a universal testing instrument with specially-made jaws. Fracture morphology was analyzed by the scanning electron microscope (SEM). Obtained data shows that the shear strength of adhesive joints for the used materials is most affected by the quality of wetting the surface of the FRC. Effect on the results could be stress distribution in adhesive strength measurements because the used jaws were not in an ideal proportion for all diameters of the samples. In another part of thesis the samples of dental pins were tested in three point bending. For the study of fracture analysis, selected samples were tested by impact in bending and test was captured with high-speed camera. With the dental pin composed of more FRC posts with a smaller diameter at the same time there is not so extensive the quarry, as in the case of using the post with a large diameter. Character of a fracture in a compound dental pin is also influenced by the type of connecting material and quality of adhesion between the material and individual posts.
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Possibilities of dispersed reinforcement for lightweight concrete
Novotná, Aneta ; Žítt, Petr (referee) ; Láník, Jaromír (advisor)
Master´s thesis deals with some problems associated with utilisation of lightweight concrete from the porous aggregates in the load – carrying structures. The thesis focuses on the possibilities of the increase of the cement composites toughness using dispersed reinforcement. Lightweight concretes were reinforced with a combination of different lengths of polypropylene fibers Forta Ferro. There were used polypropylene fibers of three lengths 19, 38, 54 mm. The thesis is divided into theoretical, experimental and static part.
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Adhesion Strength and Fracture Morphology between FRC Root Canal Post and Particulate Filled Composite Core
Kročová, Blanka ; Pavelka,, Vladimír (referee) ; Poláček, Petr (advisor)
This bachelor thesis examines the influence of composition and structure of the dental pin on its mechanical properties. It deals with the adhesion strength and fracture morphology of adhesive joints between composite, fiber stiffened root pin (FRC) and a core of particle composite. There is observed adhesive strength dependence on the diameter of the pin FRC, the fiber content of the pin and the use of the composite particle in which the pin is embedded. Shear, adhesive joint strength was measured using a universal testing instrument with specially-made jaws. Fracture morphology was analyzed by the scanning electron microscope (SEM). Obtained data shows that the shear strength of adhesive joints for the used materials is most affected by the quality of wetting the surface of the FRC. Effect on the results could be stress distribution in adhesive strength measurements because the used jaws were not in an ideal proportion for all diameters of the samples. In another part of thesis the samples of dental pins were tested in three point bending. For the study of fracture analysis, selected samples were tested by impact in bending and test was captured with high-speed camera. With the dental pin composed of more FRC posts with a smaller diameter at the same time there is not so extensive the quarry, as in the case of using the post with a large diameter. Character of a fracture in a compound dental pin is also influenced by the type of connecting material and quality of adhesion between the material and individual posts.
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