Abstract
Currently, concretes of higher compressive strengths have been produced and increasingly used by designers and contractors for both reinforced and prestressed concrete construction. The design of concrete corbels using the strut-and-tie model considers two failure modes: failure by crushing concrete in the strut and by yielding of the main steel reinforcement. To consider the failure by diagonal tension, a third equation is included in the truss plastic model proposed by Rogowsky and MacGregor. To use the truss plastic model, an efficiency factor is applied to reduce the effective concrete strength. An efficiency factor is proposed in this paper for high performance concrete. The proposed model using the new efficiency factor gives an improved correlation with experimental data. Based on the test results reported from literature review, the design method proposed by AFREM for high stregth concrete corbels is modified in this paper to make design of high strength concrete corbels more reasonable. The comparison with experimental data shows that the modified AFREM model predicts fairly well the shear capacity of the corbels.
Résumé
À ce jour, les bétons de hautes performances connaissent de multiples utilisations par des concepteurs et des constructeurs pour des éléments en béton armé et précontraints. Le dimensionnent de consoles courtes selon le modèle de bielle-et-tirant prend en considération deux types de rupture: celle par palstifiction des aciers de flexion et celle par écrasement de la bielle du béton. Pour tenir compte de la rupture diagonale des consoles, une troisième équation a été introduite dans le modèle de treillis plastique par Rogowsky et MacGregor. Pour ce modèle, nous proposons un nouveau coefficient d'efficacité pour le béton de hautes performances qui permet une meilleure corrélation avec les données expérimentales. Sur la base de résultats des essais trouvés dans la littérature, le modèle de dimensionnement des consoles en béton de hautes performances proposé par l'AFREM a été modifié afin de prédire la capacité en cisaillement des consoles.
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Editorial Note M. Saafi is a RILEM Student Member.
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Saafi, M., Toutanji, H. Design of high performance concrete corbels. Mat. Struct. 31, 616–622 (1998). https://doi.org/10.1007/BF02480612
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DOI: https://doi.org/10.1007/BF02480612