Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Strengthening Effect of Axial Circular Concrete Members Wrapped by CFRP sheet

CFRP sheet로 감싼 원형 콘크리트 압축부재의 보강 효과

  • Received : 2014.10.14
  • Accepted : 2015.05.06
  • Published : 2015.09.01
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Abstract

Many studies have been carried out on carbon fiber-reinforced plastic sheet(hereafter CFRP sheet)-confined concrete specimens for improve structural performance of concrete structures. To complement the existing studies, a parametric study is conducted to examine the effect of various design parameters such as layers of CFRP sheet, size and aspect ratio of specimens, and overlap length. The behavior of CFRP-confined concrete is compared using stress-strain curves of each specimen. And the strengthening effect of CFRP sheet is examined by maximum compressive strength. As the layers of CFRP sheet increases, structural performance of CFRP-confined concrete is significant increased. If the overlap length is more than 5% of circumstance, strengthening effect is not affected. In addition, a test database assembled from test results and existing studies is presented. Using these test database, accuracy and reliability of the existing strength models for CFRP-confined concrete are verified.

콘크리트 구조물의 내력성능을 향상시키기 위해 탄소섬유쉬트(Carbon Fiber-Reinforced Plastic Sheet, 이하 CFRP sheet)로 보강된 콘크리트에 대해 많은 연구가 수행되어 왔다. 본 연구는 CFRP sheet로 구속된 콘크리트에 대한 연구 중 미비한 부분을 보완하기 위하여 보강겹수, 시험체의 크기, 형상비, 겹이음길이를 변수로 하여 연구를 수행하였다. 각 시험체별 응력-변형률 곡선을 통해 콘크리트의 거동을 비교하였으며, 최대압축강도를 통하여 CFRP sheet의 보강효과를 확인하였다. 보강겹수의 증가에 따라 콘크리트의 압축성능은 크게 개선되었으며, 시험체의 크기와 형상비의 변화를 통해 이론적인 부분을 검증하였고, 겹이음길이는 둘레의 5%이상으로 해야만 보강효과에 영향이 없는 것으로 확인하였다. 또한 본 연구의 시험결과와 기존 시험결과를 정리하고 이를 기준으로 기존 강도추정모델을 통계 분석함으로 모델의 정확성과 신뢰성을 검증하였다.

Keywords

References

  1. Bae, J.S., Kim, K.S., Kim, J.W. and Ko, Y.P. (2000), An Experimental Study on the Strengthening Effect of CFS on Concrete Cylinder under Load History, Journal of the Korea Institute for Structural Maintenance and Inspection, Vol.4, No.3, KSMI, 169-176.
  2. Chung, L., Lee, H. K., Kim, S. C., Yoo, S. H., and Kim, J. K. (1998), Confined Effect of Concrete Compressive Members Strengthened with Carbon Fiber Laminate, Journal of the Korea Concrete Institute, Vol.10, No.6, KCI, 345-352.
  3. Demers, M., and Neale, K. W. (1994). "Strengthening of concrete columns with unidirectional composite sheets." Development in Short and Medium Span Bridge Engineering '94, Proc., 4th Int. Conf. on Short and Medium Bridges, A. A. Mufti, B. Bakht, and L. G. Jaeger, eds., Canadian Society for Civil Engineering, Montreal, 895-905.
  4. Harmon, T. G., and Slattery, K. T. (1992). "Advanced composite confinement of concrete." Proc., 1st Int. Conf. on Advanced Composite Materials in Bridges and Structures, K. W. Neale and P. Labossiere, eds., Canadian Society for Civil Engineering, Sherbrooke, Canada 299-306.
  5. Howie, I., and Karbhari, V. M. (1994). "Effect of materials architecture on strengthening efficiency of composite wraps for deteriorating columns in the North-East." Infrastructure: New Materials and Methods of Repair, Proc., 3rd Materials Engineering Conf., K. D. Basham, ed., Material Engineerin Division, ASCE, 199-206.
  6. Hwang, J. S. (2000), A Study on the Axial Behavior of the Concrete Cylinders Confined by Carbon Fiber Sheets, Journal of the Korea Institute for Structural Maintenance and Inspection, Vol.4, No.4, KSMI, 141-148.
  7. Hwang, J. S. (2001), Stress-Strain Charateristics of the Concrete Cylinders Confined by Carbon Fiber Sheets, Journal of the Architectural Institute of Korea - Structure&Construction, Vol.17, Vo.9, AIK, 57-63.
  8. Karrbhari, V. M., and Gao, Y. (1997). "Composite jacketed concrete under uniaxial compression-verification of simple design equations." J. Mater. Civ. Eng., 9(4), 185-193. https://doi.org/10.1061/(ASCE)0899-1561(1997)9:4(185)
  9. Kim, M. K. (2006), Strengthening Effect of Circular Concrete Column Wrapped with Carbon FRP Sheet, Ph.M. Dissertation, Jeju National University.
  10. Kim, Y. S. (2003), Compressive Strength Enhancement of Concrete Cylinders Confined with FRP Wrap, Ph.M. dissertation, Chung-ang University.
  11. Lam, L and Teng, J. G. (2002), Strength Models for Fiber- Reinforced Plastic-Confined Concrete, Journal of Structural Engineering, Vol. 128, No.5, ASCE, 612-623. https://doi.org/10.1061/(ASCE)0733-9445(2002)128:5(612)
  12. Lee, J. Y. and Jeong, H. S. (2003), Prediction of the Maximum Strain of Circular Concrete Columns Confined with Fiber Composites, Journal of the Korea Concrete Institute, Vol.15, No.5, KCI, 726-736. https://doi.org/10.4334/JKCI.2003.15.5.726
  13. Matthys, S., Taerwe, L., and Audenaert, K. (1999). "Test on axially loaded concrete columns confined by fiber reinforced polymer sheet wrapping." Proc., 4th Int. Symposium on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures, C. W. Dolan, S. H. Rizkalla, and A. Nanni., eds., SP-188, American Concrete Institute, Farmington, Mich., 217-229.
  14. Miyauchi, K., Nishibayashi, S., and Inoue, S. (1997). "Estimation of strengthening effects with carbon fiber sheet for concrete columns." Non-Metallic (FRP) Reinforcement for Concrete Strucures, Proc., 3rd Int. Symposium, Japan Concrete Institute, Sapporo, Japan, Vol. 1, 217-224.
  15. Miyauchi, K., Inoue, S., Kuroda, T., and Kobayashi, A. (1999). "Strengthening effects of concrete columns with carbon fiber sheet." Trans. Jpn. Concr. Inst., 21, 143-150.
  16. Modarelli, R., Micelli, F. and Monni, O. (2005) FRP-Confinement of Hollow Concrete Cylinders and Prisms, 7th International Symposium FRP Reinforcement for Concrete Structures, American Concrete Institute, Vol.2, 1029-1046.
  17. Park, Y. J. (2001), The Experimental Research on the Confinement Effect of Concrete Specimens with Carbon Fiber Sheet, Ph.M. Dissertation, Korea University.
  18. Picher, F., Rochette, P. and Labossiere, P. (1996). "Confinement of concrete cylinders with CFRP." Proc., 1st Int. Conf. on Composites for Infra-Structures, H. Saadatmanesh, and M. R. Ehsani, eds., Univ. of Arizona, Tucson, Ariz., 829-841.
  19. Shin, Y. S., Hong, Y. K., Hong, G. S., and Choi, O. C. (1995), The Strength Effects of Concrete Confined with Carbon Fiber Sheets, Journal of the Architectural Institute of Korea - Structure& Construction, Vol.11, No.10, AIK, 323-328.
  20. Soudki, K. A., and Green, M. F. (1996). "Performance of CFRP retrofitted concret columns at low temperature." Advanced Composite Materials in Bridges and Structures, Proc., 2nd Int. Conf., M. M. Elbadry ed.,Canadian Society for Civil Engineering, Montreal, 427-434.
  21. Watanable, K., Nakamura, H., Honda, T., Toyoshima, M., Iso, M., Fujimaki, T., Kaneto, M., and Shirai, N. (1997). "Confinement effect of FRP sheet on strength and ductility of concrete cylinders under uniaxial compression." Non-Metallic (FRP) Reinforcement for Concrete Structures, Proc., 3rd Int. Symposium, Japan Concrete Institute, Sapporo, Japan, Vol. 1, 233-240.
  22. Xiao, Y., and Wu, H. (2000). "Compressive behavior of concrete confined by carbon fiber composite jackets." J. Mater. Civ. Eng., 12(2), 139-146. https://doi.org/10.1061/(ASCE)0899-1561(2000)12:2(139)
  23. Youm, K. S., Lee, Y. H., Park, Y. J., and Lee, H. E. (2004), The Behavior of Concrete Confined by Carbon Fiber Sheet, Journal of Korean Society of Civil Engineers, Vol.24, No.2A, KSCE, 259-265.
  24. Zhang, S., Ye., and Mai, Y. W. (2000). "A study on polymer composites strengthening systems for concrete columns." Appl. Compos. Mater., 7, 125-138. https://doi.org/10.1023/A:1008917922156