Seismic Response of Interior RC Beam-Column Joints Upgraded with FRP Sheets. I: Experimental Study
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Volume 11, Issue 6
Abstract
In this paper, efficiency and effectiveness of carbon fiber-reinforced polymers (CFRP) in upgrading the shear strength and ductility of seismically deficient beam-column joints have been studied. For this purpose, four reinforced concrete interior beam-column sub-assemblages were constructed with nonoptimal design parameters (inadequate joint shear strength with no transverse reinforcement) representing preseismic code design construction practice of joints and encompassing the vast majority of existing beam-column connections. Out of these four, two specimens were used as baseline specimens (control specimens) and the other two were strengthened with CFRP sheets under two different schemes (strengthened specimens). In the first scheme, CFRP sheets were epoxy bonded to the joint, beams, and part of the column regions. In the second scheme, however, sheets were epoxy bonded to the joint region only but they were effectively prevented against any possible debonding through mechanical anchorages. All four subassemblages were subjected to cyclic lateral load histories so as to provide the equivalent of severe earthquake damage. Further, the damaged control specimens were repaired after filling the cracks through epoxy and wrapping them with CFRP sheets under the same two above-mentioned schemes. These repaired specimens were subjected to the similar cyclic lateral load history and their response histories were obtained. Hence, a total of six specimens were tested: two control; two strengthened; and two repaired. Response histories of control, repaired, and strengthened specimens were then compared. The results were compared through hysteretic loops, load-displacement envelopes, column profiles (maximum horizontal displacements of column along its height), joint shear distortion, ductility, and stiffness degradation. The comparison shows that CFRP sheets improve the shear resistance of the joint and increase its ductility. Results of two chosen schemes of strengthening were also compared and the importance of beam upgrading was highlighted.
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Acknowledgments
The writers wish to acknowledge financial support provided by King Abdualaziz City for Science and Technology (KACST) under Grant No. AR-21-40. They are also grateful to the technicians at the materials and structural laboratories for their assistance during execution of the experimental program of the study.
References
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.” 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(2), 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.
Li, J., Samali, B., Ye, L., and Bakoss, S. (2002). “Behaviour of concrete beam-column connections reinforced with hybrid FRP sheet.” Compos. Struct., 57(1–4), 357–365.
Mukherjee, A., and Joshi, M. (2005). “FRPC reinforced concrete beam-column joints under cyclic excitation.” Compos. Struct., 70(2), 185–199.
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.” Plastics for reinforced concrete structures, FRPRCS-5: FRPS, 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.” Proc., Int. Conf. on FRP Composites in Civil Eng., Hong Kong, Vol. I, 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.
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Information
Published In
Journal of Composites for Construction
Volume 11 • Issue 6 • December 2007
Pages: 575 - 589
Copyright
© 2007 ASCE.
History
Received: Apr 27, 2006
Accepted: Apr 19, 2007
Published online: Dec 1, 2007
Published in print: Dec 2007
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