Structural Engineering and Mechanics

  • 제72권2호
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  • Pages.155-168
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  • 2019
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  • 1225-4568(pISSN)
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  • 1598-6217(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Effectiveness of different confining configurations of FRP jackets for concrete columns

  • Moretti, Marina L. (Department of Civil Engineering, University of Thessaly)
  • 투고 : 2018.10.21
  • 심사 : 2019.05.22
  • 발행 : 2019.10.25
⟨ 이전 논문 다음 논문 ⟩

초록

This paper presents the results of an experimental investigation on the compressive strength of small scale concentrically axially loaded fiber-reinforced polymer (FRP) confined plain concrete columns, with cylinder concrete strength 19 MPa. For columns with circular (150-mm diameter) and square (150-mm side) cross sections wrapped with glass- and carbon-FRP sheets (GFRP and CFRP, respectively) applied with dry lay-up the effect of different jacket schemes and different overlap configurations on the confined characteristics is investigated. Test results indicate that the most cost effective jacket configuration among those tested is for one layer of CFRP, for both types of sections. In square sections the location of the lap length, either in the corner or along the side, does not seem to affect the confined performance. Furthermore, in circular sections, the presence of an extra wrap with FRP fibers parallel to the column's axis enhances the concrete strength proportionally to the axial rigidity of the FRP jacket. The recorded strains and the distributions of lateral confining pressures are discussed. Existing design equations are used to assess the lateral confining stresses and the confined concrete strength making use of the measured hoop strains.

키워드

참고문헌

  1. Abdelrahman, K. and El-Hacha, R. (2014), "Cost and ductility effectiveness of concrete columns strengthened with CFRP and SFRP sheets", Polymers, 6, 1381-1402. https://doi.org/10.3390/polym6051381.
  2. Au, C. and Buyukozturk, O. (2005), "Effect of fiber orientation and ply mix on fiber reinforced polymer-confined concrete", ASCE J. Compos. Constr., 9(5), 397-407. https://doi.org/10.1061/(ASCE)1090-0268(2005)9:5(397).
  3. Bisby, L.A. and Take W.A. (2009), "Strain localisations in FRPconfined concrete: new insights", Proc. ICE, Struct. Build., 162(SB5), 301-309. https://doi.org/10.1680/stbu.2009.162.5.301.
  4. Bouchelaghem, H., Bezazi, A. and Scarpa, F. (2011), "Strength of concrete columns externally wrapped with composites under compressive static loading", Reinf. Plast. Compos., 30(19), 1671-1688. https://doi.org/10.1177/0731684411424333.
  5. CEN (2004), "European Standard EN1992-1-1:2004 Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings", European Committee for Standardization, Brussels.
  6. CEN (2005), "European Standard EN1998-3:2005 Eurocode 8: Design of structures for earthquake resistance - Part 3: Assessment and retrofitting of buildings", European Committee for Standardization, Brussels.
  7. Chen, G.F., Ai, J. and Stratford, T.J. (2010), "Effect of geometric discontinuities in FRP-wrapped columns", ASCE J. Compos. Constr., 14(2), 136-145. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000053.
  8. Chen, G.F., Li, J. and Bisby, M. (2013), "Factors affecting the ultimate condition of FRP-wrapped concrete columns", ASCE J. Compos. Constr., 17(1), 67-78. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000314.
  9. Duran, B., Tunaboyu, O., Kaplan, O. and Avsar, O. (2018), "Effectiveness of seismic repairing stages with CFRPs on the seismic performance of damaged RC frames", Struct. Eng. Mech., 67(3), 233-244. https://doi.org/10.12989/sem.2018.67.3.233.
  10. Federation international du beton, fib (2001), "Externally bonded FRP reinforcement for RC structures", fib Bulletin 14. Lausanne.
  11. Fitzwilliam, J. and Bisby, P.E. (2010), "Slenderness effects on circular CFRP confined reinforced concrete columns", ASCE J. Compos. Constr., 14(3), 280-288. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000073.
  12. Harries, K.A. and Kharel, G. (2002), "Behavior and modeling of concrete subjected to variable confining pressure", ACI Mater. J., 99(2), 180-189.
  13. Harries, K.A. and Carey, S.A. (2003), "Shape and gap effects on the behavior of variably confined concrete", Cem. Concr. Research, 33, 881-890. https://doi.org/10.1016/S0008-8846(02)01085-2.
  14. Hou, D., Wu, Z., Zheng, J., Zheng, J. and Cui, Y. (2015), "Seismic rehabilitation of substandard RC columns with partially deteriorated concrete using CFRP composites", Comput. Concr., 15(1), 1-20. https://doi.org/10.12989/cac.2015.15.1.001.
  15. Ilki, A. and Kumbasar, N. (2002), "Behavior of damaged and undamaged concrete strengthened by carbon fiber composite sheets", Struct. Eng. Mech., 13(1), 75-90. https://doi.org/10.12989/sem.2002.13.1.075.
  16. Ilki, A., Kumbasar, N. and Koc, V. (2004), "Low strength concrete members externally confined with FRP sheets", Struct. Eng. Mech., 18(2), 167-194. https://doi.org/10.12989/sem.2004.18.2.167.
  17. Ilki, A., Peker, O., Karamuk, E., Demir, C. and Kumbasar, N. (2008), "FRP retrofit of low and medium strength circular and rectangular reinforced concrete columns", ASCE J. Mater. Civ. Eng., 20(2), 169-188. https://doi.org/10.1061/(ASCE)0899-1561(2008)20:2(169).
  18. Issa, M.A., Alrousan, R.Z. and Issa, M.A. (2009), "Experimental and Parametric Study of Circular Short Columns Confined with CFRP Composites", ASCE J. Compos. Constr., 13(2), 135-147. https://doi.org/10.1061/(ASCE)1090-0268(2009)13:2(135).
  19. Jiang, T. and Teng, J.G. (2007), "Analysis-oriented stress-strain models for FRP-confined concrete", Eng. Struct, 29, 2968-2986. https://doi.org/10.1016/j.engstruct.2007.01.010.
  20. Kakaletsis, D.J. (2016), "Comparative experimental assessment of seismic rehabilitation with CFRP strips and sheets on RC frames", Earthq. and Struct., 10(3), 613-628. https://doi.org/10.12989/eas.2016.10.3.613.
  21. Kocak, A. (2015), "Earthquake performance of FRP retrofitting of short columns around band-type windows", Struct. Eng. Mech., 53(1), 1-16. http://dx.doi.org/10.12989/sem.2015.53.1.001.
  22. Lam, L. and Teng, J.G. (2003), "Design-oriented stress-strain model for FRP-confined concrete", Constr. Build. Mater., 17(6-7), 471-489. https://doi.org/10.1016/S0950-0618(03)00045-X.
  23. Lam, L. and Teng, J.G. (2004), "Ultimate condition of fiber reinforced polymer-confined concrete", ASCE J. Compos. Constr., 8(6), 539-548. https://doi.org/10.1061/(ASCE)1090-0268(2004)8:6(539).
  24. Lignola, G.P., Prota, A., Manfredi, G. and Cosenza, E. (2008), "Effective strain in FRP jackets on circular RC columns", Proceedings of the 4th International Conference on FRP Composites in Civil Engineering, Zurich, July.
  25. Lim, J.C. and Ozbakkaloglu, T. (2015), "Hoop strains in FRPconfined concrete columns: experimental observations", Mater. Struct., 48, 2839-2854. https://doi.org/10.1617/s11527-014-0358-8.
  26. Lorenzis, L. and Tepfers, R. (2003), "Comparative study of models on confinement of concrete cylinders with fiber-reinforced polymer composites", Comp. Constr. 7(3), 219-237. https://doi.org/10.1061/(ASCE)1090-0268(2003)7:3(219).
  27. Moretti, M.L. and Arvanitopoulos, E. (2018), "Overlap length for confinement of carbon and glass FRP-jacketed concrete columns", Comp. Constr. 195, 14-25. https://doi.org/10.1016/j.compstruct.2018.04.038.
  28. Moshiri, N., Hosseini, A and Mostofinejad, D. (2015). "Strengthening of RC columns by longitudinal CFRP sheets: effect of strengthening technique", Constr. Build. Mat., 79, 318-325. https://doi.org/10.1016/j.conbuildmat.2015.01.040.
  29. Nistico, N., Pallini, F., Rousakis, T., Wu, Y.F. and Karabinis, A. (2014), "Peak strength and ultimate strain prediction for FRP confined square and circular concrete sections", Compos. Part B, 55, 607-634. https://doi.org/10.1016/j.compositesb.2014.07.026.
  30. Ozbakkaloglu, T. and Oelers, D.J. (2008), "Manufacture and testing of a novel FRP tube confinement system", Eng. Struct, 30, 2448-2459. https://doi.org/10.1016/j.engstruct.2008.01.014.
  31. Ozbakkaloglu, T. (2013), "Axial compressive behavior of square and rectangular high-strength concrete-filled FRP tubes", ASCE J. Compos. Constr., 17(1), 151-161. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000321.
  32. Ozbakkaloglu, T. and Lim, J.C. (2013), "Axial compressive behavior of FRP-confined concrete: Experimental test database and a new design-oriented model", Compos. Part B, 55, 607-634. https://doi.org/10.1016/j.compositesb.2013.07.025.
  33. Pessiki, S., Harries, K.A., Kestner J.T., Sause, R. and Ricles J.M. (2001), "Axial behavior of reinforced concrete columns confined with FRP jackets", ASCE J. Compos. Constr., 5(4), 237-245. https://doi.org/10.1061/(ASCE)1090-0268(2001)5:4(237).
  34. Raval, R. and Dave, U. (2013), "Behavior of GFRP wrapped RC columns of different shapes", Proced. Engin., 51, 240-249. https://doi.org/10.1016/j.proeng.2013.01.033.
  35. Rousakis, T.C., Karabinis, A.I. and Kiousis P.D. (2007), "FRPconfined concrete members: axial compression experiments and plasticity modelling", Eng. Struct., 29, 1343-1353. https://doi.org/10.1016/j.engstruct.2006.08.006.
  36. Rousakis, T.C. and Karabinis, A.I. (2008), "Substandard reinforced concrete members subjected to compression: FRP confining effects", Mater. Struct., 41, 1595-1611. https://doi.org/10.1617/s11527-008-9351-4.
  37. Sadeghian, P., Rahai, A. and Ehsani, M.R. (2010), "Effect of fiber orientation on compressive behavior of CFRP-confined concrete columns", Reinf. Plast. Compos., 29(9), 1335-1346. https://doi.org/10.1177/0731684409102985.
  38. Shahawy, M., Mirmiran, A. and Beitelman, T. (2000), "Tests and modelling of carbon-wrapped concrete columns", Compo Part B-Eng., 31(6-7), 471-480. https://doi.org/10.1016/S1359-8368(00)00021-4.
  39. Smith, S.T., Kim, S.J and Zhang, H. (2010), "Behavior and effectiveness of FRP wrap in the confinement of large concrete cylinders", ASCE J. Compos. Constr., 14(5), 573-582. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000119.
  40. Smyrou, E. (2015), "FRP versus traditional strengthening on a typical mid-rise Turkish RC building", Earthq. and Struct., 9(5), 1069-1089. http://dx.doi.org/10.12989/eas.2015.9.5.1069.
  41. Tan, K.H. (2002), "Strength enhancement of rectangular reinforced concrete columns using fiber-reinforced polymer", ASCE J. Compos. Constr., 6(3), 175-183. https://doi.org/10.1061/(ASCE)1090-0268(2002)6:3(175).
  42. Tunaboyu, O. and Avsar, O. (2017), "Seismic repair of captivecolumn damage with CFRPs in substandard RC frames", Struct. Eng. Mech., 61(1), 1-13. https://doi.org/10.12989/sem.2017.61.1.001.
  43. Wang, Z., Wang, D., Smith, S.T. and Lu D. (2012), "CFRPconfined square RC columns. I: experimental investigation", ASCE J. Compos. Constr., 16(2), 150-160. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000245.
  44. Wu, J-F. and Jiang J-F. (2013), "Effective strain of FRP for confined circular concrete columns", Compos. Struct., 95, 479-491. https://doi.org/10.1016/j.compstruct.2012.08.021.
  45. Youssef, M.N., Feng, M.Q. and Mosalam, A.S. (2007), "Stressstrain model for concrete confined by FRP composites", Compos. Part B, 38, 614-628. https://doi.org/10.1016/j.compositesb.2006.07.020.
  46. Yurdakul, O. and Avsar, O. (2015), "Seismic repair of captivecolumn damage with CFRPs in substandard RC frames", Struct. Eng. Mech., 48, 2839-2854. https://doi.org/10.12989/sem.2017.61.1.001.
  47. Xiao, Y. and Wu, H. (2000), "Compressive behavior of concrete confined by carbon fiber composite jackets", ASCE J. Mater. Civ. Eng., 12(2), 139-146. https://doi.org/10.1061/(ASCE)0899-1561(2000)12:2(139).

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