Seismic Rehabilitation of Corner RC Beam-Column Joints Using CFRP Composites
Publication: Journal of Composites for Construction
Volume 14, Issue 6
Abstract
In this paper, efficiency and effectiveness of carbon fiber reinforced polymers (CFRPs) in upgrading the shear strength and ductility of seismically deficient corner or knee reinforced concrete beam-column joints have been studied. For this purpose, four as-built corner/knee joints were constructed with no transverse reinforcement, representing extreme case of preseismic code design construction practice of joints and encompassing many existing beam-column corner joints. Out of these four as-built specimens, two specimens were used as baseline specimens (control specimens) and other two were strengthened with CFRP sheets under two different schemes (strengthened specimens). In the first scheme, CFRP sheets were epoxy bonded to joint, beams, and part of the column regions. In the second scheme, however, sheets were epoxy bonded to joint region only but they were effectively prevented against any possible debonding through mechanical anchorages. All these four subassemblages were subjected to cyclic lateral load histories to simulate loading due to earthquake and provide the equivalent of severe earthquake damage. The damaged control specimens were then repaired by filling their cracks through epoxy and externally bonding them with CFRP sheets under the same above two schemes. These repaired specimens were subjected to the similar cyclic lateral load history and their response histories were obtained. Response histories of control, repaired, and strengthened specimens were then compared. The results were compared through hysteretic loops, load-displacement envelopes, column profiles, ductility, and stiffness degradation. The comparison shows that CFRP sheets are very effective in improving shear resistance and deformation capacity of the corner beam-column joints and delaying their stiffness degradation. Shear capacities of control, repaired, and strengthened specimens were also predicted using writers’ published formulation. The predicted shear capacities were in a good agreement with the experimental values.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The experimental work conducted by the writers and described in this paper was performed at the Structural Engineering Lab of the Civil Engineering Department, King Saud University and was jointly funded by King Abdulaziz City for Science and Technology and the SBG Chair of Research and Studies in Strengthening and Rehabilitation of Structures.
References
Almusallam, T. H., and Al-Salloum, Y. A. (2007). “Seismic response of interior beam-column joints upgraded with FRP sheets. II: Analysis and parametric study.” J. Compos. Constr., 11(6), 590–600.
Al-Salloum, Y. A., and Almusallam, T. H. (2007). “Seismic response of interior beam-column joints upgraded with FRP sheets. I: Experimental study.” J. Compos. Constr., 11(6), 575–589.
Alsayed, S. H., Al-Salloum, Y. A., Almusallam, T. H., and Siddiqui, N. A. (2010). “Seismic response of FRP-upgraded exterior RC beam-column joints.” J. Compos. Constr., 14(2), 195–208.
Antonopoulos, C., and Triantafillou, T. C. (2003). “Experimental investigation of FRP-strengthened RC beam-column joints.” J. Compos. Constr., 7(1), 39–49.
Antonopoulos, C. P., and Triantafillou, T. C. (2002). “Analysis of FRP-strengthened beam-column joints.” J. Compos. Constr., 6(1), 41–51.
Baglin, P. S., and Scott, R. H. (2000). “Finite element modeling of reinforced concrete beam-column connections.” ACI Struct. J., 97(6), 886–894.
Cheung, P. C., Paulay, T., and Park, R. (1993). “Behavior of beam-column joints in seismically loaded R.C. frames.” J. Struct. Eng., 71(8), 129–138.
El-Amoury, T., and Ghobarah, A. (2002). “Seismic rehabilitation of beam-column joint using GFRP sheets.” Eng. Struct., 24(11), 1397–1407.
Gergely, J., Pantelides, C. P., and Reaveley, L. D. (2000). “Shear strengthening of RCT-joints using CFRP composites.” J. Compos. Constr., 4(2), 56–64.
Ghobarah, A., and El-Amoury, T. (2005). “Seismic rehabilitation of deficient exterior concrete frame joints.” J. Compos. Constr., 9(5), 408–416.
Ghobarah, A., and Said, A. (2001). “Seismic rehabilitation of beam-column joints using FRP laminates.” J. Earthquake Eng., 5(1), 113–129.
Ghobarah, A., and Said, A. (2002). “Shear strengthening of beam-column joints.” Eng. Struct., 24(7), 881–888.
Granata, P. J., and Parvin, A. (2001). “An experimental study on kevlar strengthening of beam-column connections.” Compos. Struct., 53, 163–171.
Hakuto, S., Park, R., and Tanaka, H. (2000). “Seismic load tests on interior and exterior beam-column joints with substandard reinforcing details.” ACI Struct. J., 97(1), 11–25.
Hanson, N. W., and Connor, H. W. (1967). “Seismic resistance of reinforced concrete beam-column joints.” J. Struct. Div., 93(5), 553–560.
Hwang, S., and Lee, H. (2000). “Analytical model for predicting shear strengths of interior reinforced concrete beam-column joints for seismic resistance.” ACI Struct. J., 97(1), 35–44.
Kam, W. Y., and Pampanin, S. (2008). “Selective weakening techniques for retrofit of existing reinforced concrete structures.” Proc., 14th World Conf. on Earthquake Engineering (14WCEE).
Li, J., Samali, B., Ye, L., and Bakoss, S. (2002). “Behaviour of concrete beam-column connections reinforced with hybrid FRP sheet.” Compos. Struct., 57, 357–365.
Mukherjee, A., and Joshi, M. (2005). “FRPC reinforced concrete beam-column joints under cyclic excitation.” Compos. Struct., 70(2), 185–199.
Pampanin, S. (2006). “Controversial aspects in seismic assessment and retrofit of structures in modern times: Understanding and implementing lessons from ancient heritage.” Bulletin of the New Zealand Society for Earthquake Engineering, 39(2), 120–133.
Pampanin, S., Bolognini, D., and Pavese, A. (2007). “Performance-based seismic retrofit strategy for existing reinforced concrete frame systems using fiber-reinforced polymer composites.” J. Compos. Constr., 11(2), 211–226.
Pantazopoulou, S., and Bonacci, J. (1992). “Consideration of questions about beam-column joints.” ACI Struct. J., 89(1), 27–36.
Pantazopoulou, S. J., and Bonacci, J. F. (1994). “On earthquake-resistant reinforced concrete frame connections.” Can. J. Civ. Eng., 21(2), 307–328.
Pantelides, C. P., Clyde, C., Lau, C. P., and Reaveley, L. D. (2001). “Seismic rehabilitation of reinforced concrete building corner joints.” Proc., 5th Int. Conf. on Fibre Reinforced Plastics for Reinforced Concrete Structures (FRPRCS-5), C. J. Burgoyne, ed., Thomas Telford, London, 309–318.
Paulay, T. (1989). “Equilibrium criteria for reinforced concrete beam-column joints.” ACI Struct. J., 86(6), 635–643.
Prota, A., Nanni, A., Manfredi, G., and Cosenza, E. (2001). “Selective upgrade of beam-column joints with composites.” Journal of FRP Composites in Civil Engineering, 1, 919–926.
Tsonos, A. G. (1999). “Lateral load response of strengthened reinforced concrete beam-to-column joints.” ACI Struct. J., 96(1), 46–56.
Zerbe, H. E., and Durrani, A. J. (1989). “Seismic response of connections in two-bay R/C frame subassemblies.” J. Struct. Eng., 115(11), 2829–2844.
Information & Authors
Information
Published In
Copyright
© 2010 ASCE.
History
Received: Sep 27, 2009
Accepted: Mar 18, 2010
Published online: Apr 6, 2010
Published in print: Dec 2010
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.