Abstract
Epoxy-bonding of FRP plates to the tensile face of RC beams has been shown to be an effective repair and strengthening technique. However, local failure by debonding or ripping of concrete cover has been reported in experiments to be a likely mode of failure due to high interfacial shear and normal stress concentrations. Predictive models for finding the interfacial shear stress have been reviewed and evaluated using experimental data reported in the literature. The most critical parameters governing the interfacial shear strength and stress as determined by the models were also examined. Through understanding of the conditions that result in debonding failure, a better approach towards designing FRP-plated RC beams against this mode of failure might be achieved.
Résumé
Le renforcement externe d'éléments en béton armé à l'aide de plaques synthétiques renforcées de fibres (FRP), s'est révélé être une technique efficace de réhabilitation des structures. Cependant, la rupture locale par décollement ou fissure du béton a été présentée dans des essais comme le mode de rupture le plus fréquent à cause de la forte concentration des contraintes de cisaillement et normales aux extrémités des plaques. Des modèles théoriques visant à trouver les contraintes de cisaillement ont été examinés et évalués en utilisant des données expérimentales rapportées dans la littérature. Les paramètres les plus critiques gouvernant la contrainte de cisaillement et la résistance au cisaillement de l'interface colle-béton, comme déterminé par les modèles théoriques, ont aussi été examinés. Pour comprendre les effets qui résultent de la rupture par décollement, une meilleure méthode de conception peut être réalisée afin d'éliminer ou de retarder ce mode de rupture.
Similar content being viewed by others
References
Bonacci, J. F. and Maalej, M., ‘Behavioral trends of RC beams strengthened with externally bonded FRP’,ASCE Journal of Composites for Construction, Accepted May 2000, in press.
Roberts, T. M. ‘Approximate analysis of shear and normal stress concentrations in the adhesive layer of plated RC beams’,The Structural Engineer 67 (12/20) (1989) 229–233.
Malek, A. M., Saadatmanesh, H. and Ehsani, R. M., ‘Prediction of failure load of R/C beams strengthened with FRP plate due to stress concentration at the plate end’,ACI structural Journal 95 (1) (1998) 142–152.
Jones, R., Swamy, R. N. and Sharif, A., ‘Plate separation and anchorage of reinforced concrete beams strengthened by epoxybonded steel plates’,The Structural Engineer 66 (5/1) (1988) 85–94.
Buyukozturk, O. and Hearing, B., ‘Failure behavior of precracked concrete beams rettrofitted with FRP’,Journal of Composites for Construction 2 (3) (1998) 138–144.
Chaallal, O., Nollet, M. J. and Perraton, D., ‘Strengthening of reinforced concrete beams with externally bonded fibre reinforced plastic plates: design guidelines for shear and flexure’,Can. J. Civ. Eng. 25 (1998) 692–704.
Triantafillou, T. C. and Plevris N., ‘Post strengthening of R/C beams with epoxy-bonded fiber composite materials’, in ‘Advanced Composite Materials’, Proceedings of the Specialty Conference, ASCE, Las Vegas, 1991 (American Society of Civil Engineers, New York, 1991) 245–256.
Roberts, T. M. and Haji-Kazemi, H., ‘A theoretical study of the behaviour of reinforced concrete beams strengthened by externally bonded steel plates’,Proc. Institution of Civil Engineers, Part 2 87 (1989) 39–55.
Saadatmanesh, H. and Ehsani, M., ‘RC beams strengthened with GFRP plates-I: experimental study’,ASCE Journal of Structural Engineering 117 (11) (1991) 3417–3433.
Sharif, A., Al-Sulaimani, G. J., Basunbul, I. A., Baluch, M. H. and Ghaleb, B. N., ‘Strengthening of initially loaded reinforced concrete beams using FRP plates’,ACI Structural Journal 91 (2) (1994) 160–168.
Arduini, M. and Nanni, A. ‘Behaviour of precracked RC beams strengthened with carbon FRP sheets’,Journal of Composites for Construction 1 (2) (1997) 63–70.
Bonacci, J. F. and Maalej, M., ‘Externally-bonded FRP for rehabilitation of corrosion damaged concrete beams’,ACI Structural Journal 97 (5) (2000) 703–711.
Spadea, G., Bencardino, F. and Swamy, R. N., ‘Structural behaviour of composite RC beams with externally bonded CFRP’,ASCE Journal of Composites for Construction 2 (3) (1998) 132–137.
Varastehpour, H. and Hamelin, P., ‘Experimental study of RC beams strengthened with CFRP plate’, in ‘Advanced Composite Materials in Bridges and Structures’, Proceedings of the Second ACMBS International Conference, Montreal, August 11–14, 1996 (CSCE, Montreal, 1996) 555–563.
Missihoun, M., ‘Renforcement en flexion de poutres en béton armé à l'aide de matériaux composites: optimisation de l'orientation des fibres’, Mémoire de Maîtrise és Sciences Appliquées, Dépt. de Génie Civil, Univ. de Sherbrooke, 1995.
Djelal, C., David, E. and Buyle-Bodin, F. (1996). ‘Utilisation de plaques en composite pour la réparation de poutres en béton armé endommagées’, in ‘Advanced Composite Materials in Bridges and Structures’, Proceedings of the Second ACMBS International Conference, Montreal, August 11–14, 1996 (CSCE, Montreal, 1996) 581–588.
Meier, U. and Kaiser, H., ‘Strengthening of structures with CFRP laminates’, in ‘Advanced Composite Materials’, Proceedings of the Specialty Conference, ASCE, Las Vegas, 1991 (American Society of Civil Engineers, New York, 1991) 224–232.
Mukhopadhyaya, P., Swamy, N. and Lynsdale, C., ‘Optimizing structural response of beams strengthened with GFRP plates’,ASCE Journal of Composites for Construction 2 (2) (1998) 87–95.
ASTM Standard E 229-97, ‘Standard test method for shear strength and shear modulus of structural adhesives’, Annual Book of ASTM Standards (American Society for Testing and Materials, Philadelphia, 1997).
Defrayne, G., ‘High performance adhesive bonding’, 1st Edn. (Society of Manufacturing Engineers, Dearborn, Michigan, 1983).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Maalej, M., Goh, W.H. & Paramasivam, P. Analysis and design of FRP externally-reinforced concrete beams against debonding-type failures. Mat. Struct. 34, 418–425 (2001). https://doi.org/10.1007/BF02482288
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02482288