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Stress-Strain Relations of Concrete According to the Confining Conditions

구속 조건에 따른 콘크리트 응력-변형률 관계

  • Received : 2005.03.31
  • Accepted : 2006.04.25
  • Published : 2006.07.31

Abstract

Confined concrete has enhanced strength and ductility compared with unconfined strength. Cause of these merits of confined concrete, many researches have been performed for confining effects of concrete and been studied in many fields. Although many researches about concrete confined by FRP sheets have been studied recently, it is difficult to apply concrete confined by FRP in real structures because FRP is a brittle material. In this study, the enhanced strength and ductility of concrete which is confined by steel tubes or steel plates were investigated. Fifty one specimens were tested and each specimen has different confining condition. Test results showed enhanced ductility and strength of confined concrete and concrete models were suggested under various confining conditions by regression of experimental data.

다축 응력 상태의 구속된 콘크리트는 구속되지 않은 콘크리트에 비해 강도가 크게 증가한다고 알려져 왔고, 많은 연구자들은 아직도 여러 분야에서 구속된 콘크리트에 대한 연구를 진행 중에 있다. 최근 FRP를 이용한 구속된 콘크리트에 대한 많은 연구가 진행 중에 있지만, FRP는 높은 강도에 비해 취성 재료여서 실제 구조물 적용에 많은 어려움이 있다. 본 연구에서는 높은 강도 및 연성을 갖는 강재로 구속된 콘크리트에 대하여 강재의 구속 강성이 콘크리트의 강도 증진 및 연성거동에 미치는 영향을 알아보기 위해 51개의 시험체를 통해 비교 분석해 보았다. 이 실험을 통해 구속된 콘크리트의 강도 증진 효과 및 연성 거동이 뛰어나게 증가함을 확인하였다. 또한 실험 결과를 회귀분석하여 구속 강성이 콘크리트 응력-변형률 곡선에 미치는 영향을 고려한 CSS(원형 강재 구속 시험체)와 R4S(사각형 이방향 강재 구속 시험체)에 대한 응력-변형률 모델을 제안하였다.

Keywords

References

  1. Chung, H.S., Yang, K.H., Lee, Y.H., and Eun, H.C. (2002) Stressstrain curve of laterally confined concrete. Engineering Structures. 24, 1153-1163 https://doi.org/10.1016/S0141-0296(02)00049-4
  2. Cusson, D. and Paultre, P. (1995) Stress-strain model for confined high-strength concrete. J. Struct. Engrg., ASCE, 121(3), 468-477 https://doi.org/10.1061/(ASCE)0733-9445(1995)121:3(468)
  3. Fafitis, A. and Shah, S.P. (1985) Predictions of ultimate behavior of confined columns subjected to large deformations. ACI J. July-August, pp. 423-433
  4. Iyengar, K.T.R.J., Desayi, P., and Reddy, K.N. (1977) Stress-strain characteristics of concrete confined in steel blinders, Magazine of Concrete Research, Vol. 22, No. 72, pp. 173-184
  5. Kent, A. Harries., Gayatri Kharel. (2003) Experimental investigation of the behavior of variably confined concrete. Cement and Concrete Res. 33, 873-880 https://doi.org/10.1016/S0008-8846(02)01086-4
  6. Mander, J.B., Priestley, M.J.N., and Park, R. (1988) Observed stress-strain behavior of confined concrete. J. Struct. Engrg., ASCE, 114(8), 1827-1849 https://doi.org/10.1061/(ASCE)0733-9445(1988)114:8(1827)
  7. Mander, J.B., Priestly, M.J.N., and Park, R. (1988) Theoretical stress-strain model for confined concrete, Journal of Structural Engineering, ASCE, V. 114, No. 8, Aug. pp. 1804-1826 https://doi.org/10.1061/(ASCE)0733-9445(1988)114:8(1804)
  8. Popovics, S. (1973) A numerical approach to complete stress-strain curve of concrete. Cement and Concrete Res. 3, pp. 583-599 https://doi.org/10.1016/0008-8846(73)90096-3
  9. Saatcioglu, M. and Razvi, S.R. (1992) Strength and ductility of confined concrete, Journal of Structural Engineering ASCE, Vol. 118, No. 6, pp. 1560-1607
  10. Saatcioglu, M. and Razvi, S.R. (1999) Confinement model for high-strength concrete. Journal of Structural Engineering ASCE, Vol. 125, No. 3, pp. 281-289 https://doi.org/10.1061/(ASCE)0733-9445(1999)125:3(281)
  11. Yong, Y.K., Nour, M.G., and Nawy, E.G. (1988) Behavior of laterally confined high-strength concrete under axial loads. Journal of Structural Engineering ASCE, Vol. 114, No. 2, pp. 332-351 https://doi.org/10.1061/(ASCE)0733-9445(1988)114:2(332)