Experimental and analytical assessment of SRF and aramid composites in retrofitting RC columns

  • Dang, Hoang V. (Department of Architectural Engineering, Sejong University) ;
  • Shin, Myoungsu (School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology) ;
  • Han, Sang Whan (Department of Architectural Engineering, Hanyang University) ;
  • Lee, Kihak (Department of Architectural Engineering, Sejong University)
  • Received : 2014.04.25
  • Accepted : 2014.08.16
  • Published : 2014.11.25


This research aimed to investigate retrofitting methods for damaged RC columns with SRF (Super Reinforced with Flexibility) and aramid composites and their impacts on the seismic responses. In the first stage, two original (undamaged) column specimens, designed to have a flexural- or shear-controlled failure mechanism, were tested under quasi-static lateral cyclic and constant axial loads to failure. Afterwards, the damaged column specimens were retrofitted, utilizing SRF composites and aramid rods for the flexural-controlled specimen and only SRF composites for the shear-controlled specimen. In the second stage, the retrofitted column specimens were tested again under the same conditions as the first stage. The hysteretic responses such as strength, ductility and energy dissipation were discussed and compared to clarify the specific effects of each retrofitting material on the seismic performances. Generally, SRF composites contributed greatly to the ductility of the specimens, especially for the shear-controlled specimen before retrofitting, in which twice the deformation capacity was obtained in the retrofitted specimen. The shear-controlled specimen also experienced a flexural failure mechanism after retrofitting. In addition, aramid rods moderately fortified the specimen in terms of the maximum shear strength. The maximum strength of the aramid-retrofitted specimen was 12% higher than the specimen without aramid rods. In addition, an analytical modeling of the undamaged specimens was conducted using Response-2000 and Zeus Nonlinear in order to further validate the experimental results.


SRF composites;aramid rods;hysteretic behavior;displacement ductility;seismic retrofit


Supported by : NRF, KAIA


  1. Chang, C., Kim, S.J., Park, D. and Choi, S. (2014), "Experimental investigation of reinforced concrete columns retrofitted with polyester sheet", Earthq. Struct., 6(3), 237-250.
  2. ACI (2011), Building code requirements for structural concrete (ACI 318-11) and commentary (ACI 318R-11), American Concrete Institute.
  3. Aboutaha, R.S., Engelhardt, M.D., Jirsa, J.O. and Kreger, M.E. (1994), "Seismic shear strengthening of RC columns using rectangular steel jackets", Fifth U.S National Conference on Earthquake Engineering, July, Chicago, Illinois, 799-808.
  4. Bayrak, O., Lacobucci, R.D. and Sheikh, S.A. (2003), "Retrofit of square concrete with carbon fiber-reinforced polymer for seismic resistance", ACI Struct. J., 100(6), 785-794.
  5. Choi, S.W., Kim, Y. and Park, H.S. (2014), "Multi-objective seismic retrofit method for using FRP jackets in shear-critical reinforced concrete frames", Compos Part B., 56, 207-216.
  6. Colomb, F., Tobbi, H., Ferrier, E. and Hamelin, P. (2008), "Seismic retrofit of reinforced concrete short columns by CFRP materials", Compos. Struct., 82, 475-487.
  7. Dai, J.G., Lam, L. and Ueda, T. (2012), "Seismic retrofit of square RC columns with polyethylene terephthalate (PET) fibre reinforced polymer composites", Construct. Build Mater., 27, 206-217.
  8. Elnashai, A.S., Papanikolaou, V. and Lee, D. (2004), "Zeus NL - a system for inelastic analysis of structures", Mid-America Earthquake Center CD-Release 04, University of Illinois at Urbana-Champaign.
  9. Ghobarah, A. and Galal, K.E. (2004), "Seismic rehabilitation of short rectangular RC columns", J. Earthq. Eng., 8(1), 45-68.
  10. Han, S.W. and Jee, N.Y. (2005). "Seismic behaviors of columns in ordinary and intermediate moment resisting concrete frames", Eng. Struct., 27, 951-962.
  11. Kim, Y., Kabeyasawa, T. and Igarashi, S. (2012), "Dynamic collapse test on eccentric reinforced concrete structures with and without seismic retrofit", Eng. Struct., 34, 95-110.
  12. Haroun, M.A. and Elsanadedy, H.M., (2005), "Behavior of Cyclically Loaded Squat Reinforced Concrete Bridge Columns Upgraded with Advanced Composite-Material Jackets", J. Bridge Eng., ASCE, November - December, 741-748.
  13. Kabeyasawa, T., Tasai, A. and Igarashi, S. (2002), "An economical and efficient method of strengthening reinforced concrete columns against axial load collapse during major earthquake", The Third Workshop on Performance-based Engineering on Reinforced Concrete Building Structures, Seattle, WA. PEER Report 2002/02, 371-384
  14. Kabeyasawa, T., Tasai, A. and Igarashi, S. (2004), "Test and analysis of reinforced concrete columns strengthened with polyester sheet", Proceedings of 13th World Conference on Earthquake Engineering, Vancouver, B.C., Canada, August.
  15. Le, T.K., Lee, K., Lee, J., Lee, D. and Woo, S. (2010), "Experimental study of RC beam-column joints strengthened using CFRP composites", Compos. Part B., 134(8), 1288-1299.
  16. Le, T.K., Lee, K., Shin, M. and Lee, J. (2011), "Analytical assessment and modeling of RC beam-column connections strengthened with CFRP composites", Compos. Part B., 42, 1786-1798.
  17. Lee, D.H. and Elnashai, A.S. (2001), "Seismic analysis of RC bridge columns with flexure-shear interaction", J. Struct. Eng., 127(5), 546-553.
  18. Meshaly, M.E., Youssef, M.A. and Elfath, H.M.A. (2014), "Use of SMA bars to enhance the seismic performance of SMA braced RC frames", Earthq. Struct., 6(3), 267-280.
  19. Ozcan, O., Binici, B. and Ozcebe, G. (2008), "Improving seismic performance of deficient reinforced concrete piers using carbon fiber-reinforced polymers", Eng Struct., 30, 1632-1646.
  20. Park, R. (1989), "Evaluation of ductility of structures and structural assemblages from laboratory testing", Bulletin of the New Zealand National Society for Earthquakes Engineering, 22(3), 155-166.
  21. Priestley, M.J.N., Verma, R. and Xiao, Y. (1994), "Seismic shear strength of reinforced concrete columns", J. Struct. Eng. - ASCE, 120(8), 2310-2329.
  22. Priestley, M.J.N., Seible, F., Xiao, Y. and Verma, R. (1994), "Steel jacket retrofitting concrete bridge columns for enhanced shear strength-part 2: Test results and comparison with theory", ACI Struct. J., 91(5), 537-551.
  23. Sause, R., Harrries K.A., Walkup, S.L., Pessiki, S. and Ricles, J.M. (2004), "Flexural behavior of concrete piers retrofitted with carbon fiber-reinforced polymer jackets", ACI Struct. J., 101-S70:708-716.
  24. Seible, F., Priestley, M.J.N., Hegemier, G.A. and Innamorato, D. (1997), "Seismic retrofitting of RC with continuous carbon fiber jackets", J. Compos. Construct., 52-62.
  25. Sezen, H. and Chowdhury, T. (2009). "Hysteretic model for reinforced concrete columns including the effect of shear and axial load failure", J Struct Eng, ASCE, 135(2), 139-146.
  26. Sezen, H. and Moehle, J.P. (2006), "Seismic tests of concrete columns with light transverse reinforcement", ACI Struct. J., 103(6), 842-849.
  27. Scott, B.D., Park, R. and Priestley, M.J.N. (1982), "Stress-strain behavior of concrete confined by overlapping hoops at low and high strain rates", J. Am. Concrete Inst., 79(1), 13-27.
  28. Shin, M., Choi, Y., Kim, I. and Lee, K. (2013), "Effectiveness of low-cost fiber reinforced cement composites in hollow columns under cyclic loading", Construct. Build. Mater., 47, 623-635.