DOI QR코드

DOI QR Code

Slender RC columns strengthened with combined CFRP and steel jacket under axial load

Lu, Yi-yan;Li, Na;Li, Shan;Ou, Tian-yan

  • 투고 : 2014.02.19
  • 심사 : 2015.04.15
  • 발행 : 2015.11.25

초록

This paper presents an experimental study on the effectiveness of simultaneous application of carbon fiber-reinforced polymer (CFRP) and steel jacket in strengthening slender reinforced concrete (RC) column. The columns were 200 mm square cross section with lengths ranging from 1600 to 3000 mm. Ten columns were tested under axial load. The effects of the strengthening technique, slenderness ratio, cross-section area of steel angle and CFRP layer number were examined in terms of axial load-axial strain curve, CFRP strain, steel strip strain and steel angle strain. The experiments indicate that strengthening RC columns with combined CFRP and steel jacket is effective in enhancing the load capacity, ductility and energy dissipation capacity of RC column. Based on the existing models for RC columns strengthened with CFRP and with steel jacket, a design formula considering a slenderness reduction factor is proposed to predict the load capacity of the RC columns strengthened with combined CFRP and steel jacket. The predictions agree well with the experimental results.

키워드

reinforced concrete column;strengthening;steel jacket;CFRP;axial load;load capacity

참고문헌

  1. ACI 440.2R-02 (2002), Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures, Farmington Hills, MI, USA.
  2. Badalament, V., Campione, G. and Mangiavillano, M.L. (2010), "Simplified model for compressive behavior of concrete columns strengthened by steel angles and strips", J. Eng. Mech., 136(2), 230-238. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000069
  3. Bai, Y.L., Dai, J.G. and Teng, J.G. (2014), "Cyclic compressive behavior of concrete confined with large rupture strain FRP composites", J. Compos. Constr., 18(1), 04013025. DOI: 10.1061/(ASCE)CC.1943-5614.0000386 https://doi.org/10.1061/(ASCE)CC.1943-5614.0000386
  4. Campione, G. (2012a), "Load carrying capacity of RC compressed columns strengthened with steel angles and strips", Eng. Struct., 40, 457-465. https://doi.org/10.1016/j.engstruct.2012.03.006
  5. Campione, G. (2012b), "Strength and ductility of R.C. columns strengthened with steel angles and battens", Constr. Build. Mater., 35, 800-807. https://doi.org/10.1016/j.conbuildmat.2012.04.090
  6. Campione, G., Colajanni, P. and La, M.L. (2007), "Ductility of reinforced concrete members externally wrapped with fiber-reinforced polymer sheets", J. Compos. Constr., 11(3), 279-290. https://doi.org/10.1061/(ASCE)1090-0268(2007)11:3(279)
  7. Cirtek, L. (2001), "RC columns strengthened with bandage - experimental programme and design recommendations", Constr. Build. Mater., 15(8), 341-349. https://doi.org/10.1016/S0950-0618(01)00015-0
  8. Dai, J.G., Bai, Y.L. and Teng, J.G. (2011), "Behavior and Modeling of Concrete Confined with FRP Composites of Large Deformability", J. Compos. Constr., 15(6), 963-973. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000230
  9. El-Hacha, R. and Mashrik, M.A. (2012), "Effect of SFRP confinement on circular and square concrete columns" Eng. Struct., 36, 379-393. https://doi.org/10.1016/j.engstruct.2011.12.006
  10. El-Hacha, R. and Abdelrahman, K. (2013), "Slenderness effect of circular concrete specimens confined with SFRP sheets", Compos. Part B- Eng., 44(1), 152-166. https://doi.org/10.1016/j.compositesb.2012.06.014
  11. Eurocode 3 (1993), Design of steel structures. Part 1-1: General rules and rules for buildings, Brussels, Belgium.
  12. Eurocode 4 (2004), Design of composite steel and concrete structures. Part 1-1: General rules and rules for buildings, Brussels, Belgium.
  13. Eurocode 8 (2003), Design of structures for earthquake resistance. Part 3: Strengthening and repair of buildings, Brussels, Belgium.
  14. Gajdosova, K. and Bilcik, J. (2013), "Full-Scale Testing of CFRP-Strengthened Slender Reinforced Concrete Columns", J. Compos. Constr., 17(2), 239-248. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000329
  15. Gimenez, E., Adam, J.M., Ivorra, S. and Calderon, P.A. (2009), "Influence of strips configuration on the behaviour of axially loaded RC columns strengthened by steel angles and strips", Mater. Design, 30(10), 4103-4111. https://doi.org/10.1016/j.matdes.2009.05.010
  16. Harrie, K.A. and Carey, S.A. (2003), "Shape and "gap" effects on the behavior of variably confined concrete", Cement Concrete Res., 33(6), 881-890. https://doi.org/10.1016/S0008-8846(02)01085-2
  17. Ilki, A., Peker, O. and Karamuk, E. (2008), "FRP retrofit of low and medium strength circular and rectangular reinforced concrete columns", J. Mater. Civil Eng., 20(2), 169-188. https://doi.org/10.1061/(ASCE)0899-1561(2008)20:2(169)
  18. Li, J.B., Gong, J.X. and Wang, L.C. (2009), "Seismic behavior of corrosion-damaged reinforced concrete columns strengthened using combined carbon fiber-reinforced polymer and steel jacket", Constr. Build. Mater., 23(7), 2653-2663. https://doi.org/10.1016/j.conbuildmat.2009.01.003
  19. Lu, Y.Y., Shi, J.Y. and Zhao, G.F. (2003), "Experimental research on concrete columns strengthened with the combination of CFRP and angle steel", J. Build. Struct., 24(5), 18-23.
  20. Lu, Y.Y., Chen, S.X. and Zhao, G.F. (2005), "An experimental study on the seismic behavior of reinforced concrete columns strengthened with bonded steel hoops and carbon fiber reinforced polymer sheet", China Civ. Eng. J., 38(8), 10-17.
  21. Lu, Y.Y., Tong, G.B. and Zhang, H.J. (2006), "Experimental research on RC eccentric compression column strengthened with the combination of CFRP and angle steel", J. Build. Struct., 27(1), 106-111.
  22. Lu, Y.Y., Zhang, H. and Zhang, H.J. (2007), "Experimental study on the shear behavior of reinforced concrete columns strengthened with bonded steel angles combining with carbon fiber reinforced polymer sheets", China Civ. Eng. J., 40(10), 1-7.
  23. Maaddawy, T.E., Sayed, M.E. and Abdel-Magid, B. (2010), "The effects of cross-sectional shape and loading condition on performance of reinforced concrete members confined with Carbon Fiber-Reinforced Polymers", Mater. Design, 31(5), 2330-2341. https://doi.org/10.1016/j.matdes.2009.12.004
  24. Montuori, R. and Piluso, V. (2009), "Reinforced concrete columns strengthened with angles and battens subjected to eccentric load", Eng. Struct., 31(2), 539-550. https://doi.org/10.1016/j.engstruct.2008.10.005

과제정보

연구 과제 주관 기관 : Natural Science Foundation of China, Natural Science Foundation of Hubei Province, Central Universities