Seismic Performance of CFRP-Retrofitted Large-Scale Square RC Columns with High Axial Compression Ratios
Publication: Journal of Composites for Construction
Volume 21, Issue 5
Abstract
Numerous reinforced concrete frames have collapsed in major earthquakes because of severe local damage at the ends of columns. Many of these frames were designed and built according to out-of-date codes in which earthquake loads were either not taken into account or not sufficiently considered. To date, there are still a large number of such nonductile RC frames serving in the potential earthquake regions across the world. Thus, there is an urgent need for preearthquake retrofitting and strengthening of these RC frames to achieve desirable seismic performance. In this paper, a total of 11 large-scale cantilever square RC columns were constructed and nine of them were retrofitted with carbon fiber-reinforced polymers (CFRP) wraps at the column ends. These columns were then tested under combined constant axial compression and cyclic lateral displacement excursions. The variables in the tests included the axial compression ratio, the thickness of CFRP wraps, and the column size. The failure modes, hysteretic responses, energy dissipation, stiffness degradation, and equivalent viscous damping ratio of the tested columns were presented and interpreted. The test results showed that the ductility and energy dissipation capacities of nonductile RC columns can be significantly improved with the potential plastic hinge regions of the columns being retrofitted. The retrofitted columns were found to exhibit satisfactory seismic performance even when tested under an ultrahigh axial compression level (i.e., 0.75). Based on the test results, the degradation of the effective stiffness and the unloading stiffness of the columns was discussed and empirical equations were proposed through nonlinear regression analysis.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (Grant Nos. 51408153, 51478143, and 51278150), the National Key Basic Research Program of China (973 Program, Grant No. 2012CB026200), and the China Postdoctoral Science Foundation (Grant Nos. 2014M551252 and 2015T80354).
References
ASTM. (1989). “Standard test method for tensile properties of polymer matrix composite materials.” ASTM D3039/D3039M-08, West Conshohocken, PA.
Cai, Z. K., Wang, D. Y., Smith, S. T., and Wang, Z. Y. (2016). “Experimental investigation on the seismic performance of GFRP-wrapped thin-walled steel tube confined RC columns.” Eng. Struct., 110, 269–280.
CECS (China Association for Engineering Construction Standardization). (2003). “Technical specification for strengthening concrete structures with carbon fiber reinforced polymer laminate.” CECS146-2003, Beijing (in Chinese).
Clough, R. W., and Penzien, J. (1993). Dynamics of structures, 2nd Ed., McGraw Hill, New York.
Colomb, F., Tobbi, H., Ferrier, E., and Hamelin, P. (2008). “Seismic retrofit of reinforced concrete short columns by CFRP materials.” Compos. Struct., 82(4), 475–487.
Dai, J. G., Lam, L., and Ueda, T. (2012). “Seismic retrofit of square RC columns with polyethylene terephthalate (PET) fibre reinforced polymer composites.” Constr. Build. Mater., 27(1), 206–217.
Galal, K., Arafa, A., and Ghobarah, A. (2005). “Retrofit of RC square short columns.” Eng. Struct., 27(5), 801–813.
Ghosh, K. K., and Sheikh, S. A. (2007). “Seismic upgrade with carbon fiber-reinforced polymer of columns containing lap-spliced reinforcing bars.” ACI Struct. J., 104(2), 227–236.
Gu, D. S., Wu, G., Wu, Z. S., and Wu, Y. F. (2010). “Confinement effectiveness of FRP in retrofitting circular concrete columns under simulated seismic load.” J. Compos. Constr., 531–540.
Hosseini, A., Khaloo, A. R., and Fadaee, S. (2005). “Seismic performance of high-strength concrete square columns confined with carbon fiber reinforced polymers (CFRPs).” Canad. J. Civ. Eng., 32(3), 569–578.
Iacobucci, R. D., Sheikh, S. A., and Bayrak, O. (2003). “Retrofit of square concrete columns with carbon fiber-reinforced polymer for seismic resistance.” ACI Struct. J., 100(6), 785–794.
Idris, Y., and Ozbakkaloglu, T. (2013). “Seismic behavior of high-strength concrete-filled FRP tube columns.” J. Compos. Constr., .
Jiang, C., Wu, Y. F., and Wu, G. (2014). “Plastic hinge length of FRP-confined square RC columns.” J. Compos. Constr., .
Liu, J., and Sheikh, S. A. (2013). “Fiber-reinforced polymer-confined circular columns under simulated seismic loads.” ACI Struct. J., 110(6), 941–951.
Lu, B. G., and Silva, P. F. (2006). “Estimating equivalent viscous damping ratio for RC members under seismic and blast loadings.” Mech. Res. Commun., 33(6), 787–795.
Ma, G., and Li, H. (2015). “Experimental study of the seismic behavior of predamaged reinforced-concrete columns retrofitted with basalt fiber-reinforced polymer.” J. Compos. Constr., .
Ma, R., Xiao, Y., and Li, K. (2000). “Full-scale testing of a parking structure column retrofitted with carbon fiber reinforced composites.” Constr. Build. Mater., 14(2), 63–71.
Mahin, S. A., and Bertero, V. V. (1976). “Problems in establishing and predicting ductility in aseismic design.” Proc., Int. Symp. on Earthquake Structural Engineering, St. Louis, MO, 613–628.
Mahin, S. A., and Bertero, V. V. (1981). “An evaluation of inelastic seismic design spectra.” J. Struct. Eng., 107(9), 1777–1795.
Memon, M. S., and Sheikh, S. A. (2005). “Seismic resistance of square concrete columns retrofitted with glass fiber-reinforced polymer.” ACI Struct. J., 102(5), 774–783.
Ministry of Construction of the People’s Republic of China. (1989). “Code for seismic design of buildings.” GBJ11-89, Beijing (in Chinese).
Ministry of Construction of the People’s Republic of China. (2006). “Design code for strengthening concrete structure.” GB50367-2006, China Architecture and Building Press, Beijing (in Chinese).
MOHURD (Ministry of Housing and Urban-Rural Development of the People’s Republic of China). (2010a). “Code for seismic design of buildings.” GB50011-2010, China Architecture and Building Press, Beijing (in Chinese).
MOHURD (Ministry of Housing and Urban-Rural Development of the People’s Republic of China). (2010b). “Technical code for infrastructure application of FRP composites.” GB50608-2010, China Planning Press, Beijing (in Chinese).
OpenSees [Computer software]. Univ. of California, Berkeley, CA.
Ozbakkaloglu, T., and Saatcioglu, M. (2006). “Seismic performance of high-strength concrete columns confined by fiber-reinforced polymer tubes.” J. Compos. Constr., 538–549.
Ozbakkaloglu, T., and Saatcioglu, M. (2007). “Seismic performance of square high-strength concrete columns in FRP stay-in-place formwork.” J. Struct. Eng., 44–56.
Ozcan, O., Binici, B., and Ozcebe, G. (2008). “Improving seismic performance of deficient reinforced concrete columns using carbon fiber-reinforced polymers.” Eng. Struct., 30(6), 1632–1646.
Paultre, P., Boucher-Trudeau, M., Eid, R., and Roy, N. (2015). “Behavior of circular reinforced-concrete columns confined with carbon fiber-reinforced polymers under cyclic flexure and constant axial load.” J. Compos. Constr., .
Promis, G., and Ferrier, E. (2012). “Performance indices to assess the efficiency of external FRP retrofitting of reinforced concrete short columns for seismic strengthening.” Constr. Build. Mater., 26(1), 32–40.
Promis, G., Ferrier, E., and Hamelin, P. (2009). “Effect of external FRP retrofitting on reinforced concrete short columns for seismic strengthening.” Compos. Struct., 88(3), 367–379.
Realfonzo, R., and Napoli, A. (2009). “Cyclic behavior of RC columns strengthened by FRP and steel devices.” J. Struct. Eng., 1164–1176.
Seible, F., Priestley, M. N., Hegemier, G. A., and Innamorato, D. (1997). “Seismic retrofit of RC columns with continuous carbon fiber jackets.” J. Compos. Constr., 52–62.
Sheikh, S. A., and Khoury, S. S. (1993). “Confined concrete columns with stubs.” ACI Struct. J., 90(4), 414–431.
Sheikh, S. A., and Li, Y. (2007). “Design of FRP confinement for square concrete columns.” Eng. Struct., 29(6), 1074–1083.
Sheikh, S. A., and Yau, G. (2002). “Seismic behavior of concrete columns confined with steel and fiber-reinforced polymers.” ACI Struct. J., 99(1), 72–80.
Tirasit, P., and Kawashima, K. (2007). “Seismic performance of square reinforced concrete columns under combined cyclic flexural and torsional loadings.” J. Earthq. Eng., 11(3), 425–452.
Wang, D. Y., Wang, Z. Y., Smith, S. T., and Yu, T. (2016). “Size effect on axial stress-strain behavior of CFRP-confined square columns.” Constr. Build. Mater., 118, 116–126.
Wang, Z. Y., Wang, D. Y., Smith, S. T., and Lu, D. G. (2012). “CFRP-confined square RC columns. I: Experimental investigation.” J. Compos. Constr., 150–160.
Wu, Y. F., Liu, T., and Wang, L. (2008). “Experimental investigation on seismic retrofitting of square RC columns by carbon FRP sheet confinement combined with transverse short glass FRP bars in bored holes.” J. Compos. Constr., 53–60.
Xiao, Y., and Ma, R. (1997). “Seismic retrofit of RC circular columns using prefabricated composite jacketing.” J. Struct. Eng., 1357–1364.
Ye, L. P., Yue, Q. R., Zhao, S. H., and Li, Q. W. (2002). “Shear strength of reinforced concrete columns strengthened with carbon-fiber-reinforced plastic sheet.” J. Struct. Eng, 1527–1534.
Youssf, O., ElGawady, M. A., and Mills, J. E. (2015). “Displacement and plastic hinge length of FRP-confined circular reinforced concrete columns.” Eng. Struct., 101, 465–476.
Zohrevand, P., and Mirmiran, A. (2012). “Cyclic behavior of hybrid columns made of ultra high performance concrete and fiber reinforced polymers.” J. Compos. Constr., 91–99.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 21 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Jun 1, 2016
Accepted: Jan 25, 2017
Published online: Apr 8, 2017
Discussion open until: Sep 8, 2017
Published in print: Oct 1, 2017
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.