Ce travail porte sur l'étude du comportement mécanique d'une console courte en béton armé renforcée par collage de tissus en fibres de carbone et en particulier sur l'influence du nombre de couches de tissus en fibres de carbone, du type du renforcement, de l'orientation des tissus composites, du type de tissus en fibres de carbone. Les résultats montrent que la performance de la console n‘augmente pas linéairement en fonction de l'épaisseur de la plaque composite. Il existe une épaisseur optimale de tissus en fibres de carbone. Dans le cas du renforcement sur les deux faces du béton, il existe un nombre de couches optimales. Dans le cas du renforcement par bandage, l'épaisseur de matériaux composites plus intéressants est de trois couches. Par contre, la résistance de la console renforcée dépend fortement de la surface renforcée. Les résultats montrent également que le comportement d'une console renforcée peut être présenté en trois phases: la phase élastique globale, la phase de la propagation de fissures et la phase de l'ouverture des fissures diagonales. Le renforcement de la console permet d'augmenter considérablement la résistance ultime de 20 à 82% et la rigidité de la console. Les ruptures des consoles renforcées peuvent être résumées en cinq modes. En se basant sur les résultats obtenus et les modèles existants, la résistance ultime de la console renforcée et non renforcée a été estimée et analysée. Un modèle basant sur lа théorie de l'endommagement a été développé dans ce travail. L'effet de fatigue sur le comportement et sur la résistance ultime de la console courte renforcée a été également étudié dans ce travail. / This study deals with mechanical behaviour of strengthening reinforced concrete corbel by bonding carbon fibre sheet and in particular the influence of the number of layers of carbon fiber fabric, the type of strengthening, the orientation of the composite fabric and the type of carbon fiber fabrics .The results show that the performance of the corbel does not increase linearly with the thickness of the composite plate. There is an optimum thickness of the carbon fiber fabrics. In the case of strengthening on both sides of the concrete, there are an optimum number of layers. In the case of fully wrapped strengthening, the most interesting thickness of the composite is three layers. However, the resistance of the strengthening reinforced concrete corbel depends strongly on the bonded surface.The results also show that the behavior of strengthening corbel can be presented in three phases: the overall elastic phase, the phase of crack propagation and the phase of the opening of diagonal cracks. Strengthening the corbel can significantly increase the ultimate strength from 20% to 82 % and the stiffness of the corbel. The failure of the strengthening corbel can be summarized in five modes.Based on the results obtained and the existing models, the ultimate strength of the strengthening corbel or without strengthening, was estimated and analyzed. A model based on damage theory has been developed in this work. The effect of fatigue on the behavior and ultimate strength of the reinforced concrete corbel has also been studied.

The diploma thesis deals with the strenghtening of the supporting parts of the production hall in Drásov. In the first part the existing load bearing capacity of the structure is solved. The next step is to design of strenghtening variants for nonconforming columns and short corbel. Columns and short corbel are strenghtening with monostrand. At the end of the thesis, verification of the load bearing capacity of the strenghtening structure is performed.

The master´s thesis deals with concrete properties and it introduces problematics of building survey. In each part the study deals with diagnostic methods used for building construction. Then it closely examines selected methods, which are used for recognisability of steel reinforcement in concrete. In the practical part I conducted two engineering surveys of reinforced concrete industrial buildings. The main aims were to identify the position of reinforcement in selected elements of crane runway and to evaluate the quality of used concrete. The last part of thesis is focused on static assessment of short corbel of crane runway.