KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Predictions of Curvature Ductility Factor of Reinforced Concrete Beam Sections Used High Strength Concrete and Steel

고강도 재료를 사용한 철근콘크리트 보 단면의 곡률연성지수 예측

  • 이형준 (한밭대학교 건설환경공학과)
  • Received : 2012.11.27
  • Accepted : 2013.03.07
  • Published : 2013.03.30
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Abstract

The high strength materials have been more widely used in a large reinforced concrete structures. It is known that the use of high strength material in RC structures give the benefits of the mechanical and durable properties, but the ductility decreases with an increase in the strength of the materials. In the design of a reinforced concrete beam, both the flexural strength and ductility need to be considered. So, it is necessary to assess accurately the ductility of the beam with high strength materials in order to ensure the ductility requirement in design. In this study, the effects of the material strength on the flexural behavior and curvature ductility factor of reinforcement concrete beam sections with various reinforcement conditions have been evaluated and a newly prediction formula for curvature ductility factor of RC beam has been developed considering the stress of compression reinforcement at ultimate state. The proposed predictions for the curvature ductility factor which is applicable to both singly and doubly reinforced concrete beam are verified by comparisons with other prediction formulas and the proposed formula offers fairly accurate within 9% error and consistent predictions for curvature ductility factor of reinforced concrete beam.

콘크리트 구조물의 대형화에 따라 고강도를 갖는 재료가 최근에 많이 사용되고 있는 추세이다. 고강도 재료의 사용은 역학적 성질 또는 내구성에 있어서는 장점이 있으나 구조물의 연성 거동에는 불리한 것으로 알려져 있다. 철근콘크리트 부재는 강도뿐만 아니라 적절한 연성이 확보되도록 설계가 되어야 하기 때문에 철근콘크리트 보의 연성을 적절하게 평가할 수 있어야 한다. 본 연구에서는 고강도 재료를 사용한 철근콘크리트 보부재의 곡률연성지수의 예측식을 제시하고자 하였다. 이를 위하여 고강도 콘크리트 및 철근을 사용한 직사각형 단면 RC 보의 모멘트-곡률 관계를 해석적 방법으로 계산하여 다양한 철근 배치 조건하에서 콘크리트 및 철근의 강도가 부재의 휨거동 및 곡률연성지수에 미치는 영향을 분석하였고, 단철근 및 복철근 보에 모두 적용할 수 있는 극한상태에서의 압축철근의 응력을 고려한 새로운 곡률연성지수 예측식을 도출하였다. 제안한 곡률연성지수 예측식은 기존의 식과 비교분석하였으며, 단철근 및 복철근 보에서 예측식에 의해 계산된 곡률연성지수는 수치해석에 의해 얻은 곡률연성지수 값을 오차 범위 9% 내에서 예측하는 것으로 나타났다.

Keywords

References

  1. American Concrete Institute (ACI) (2008), Building Code Requirements for Structural Concrete (ACI 318M-08) and Commentary, Farmington Hills, Detroit, USA. 473pp.
  2. Arslan, G., and Cihanli, E. (2010), "Curvature Ductility Prediction of Reinforced High-Strength Concrete Beam Sections", Journal of Civil Engineering and Management, Vol. 16, No. 4, pp. 462-470. https://doi.org/10.3846/jcem.2010.52
  3. Attard, M.M., and Setunge, S. (1996), "The Stress-Strain Relationship of Confined and Unconfined Concrete", ACI Materials Journal, ACI. Vol. 93, No. 5, pp. 432-444.
  4. Bai, Z.Z., and Au, F.T.K. (2011), "Flexural Ductility Design of High-Strength Concrete Beams", The Structural Design of Tall Special Buildings, http://dx.doi.org/10.1002/tal.714.
  5. European Committee for Standardization (EC2) (2004), Eurocode 2 : Design of Concrete Structures, Part1-1 : General Rules and Rules for buildings(EN 1992-1-1:2004), Brussels, 227pp.
  6. Ho, J.C.M., Kwan, A.K.H., and Pam, H.J. (2003), "Theoretical Analysis of Post-Peak Behavior of Normal and High Strength Concrete Beams", The Structural Design of Tall Special Buildings, pp.109-125, http://dx.doi.org /10.1002/tal.216.
  7. Hong, G.-H. (2011), "Flexural Performance Evaluation of Reinforced Concrete Beams with High-Strength Concrete and Reinforcing Bars", Journal of Architectural Institute of Korea, Architectural Institute of Korea, Vol. 27, No. 6, pp. 49-56 (in Korean).
  8. Jang, I.Y., Park, H.G., Kim, S.S., Kim, J.H., and Kim. Y.G. (2008), "On the Ductility of High-Strength Concrete Beams", International Journal of Concrete Structures and Materials, Korea Concrete Institute, Vol. 2, No. 2, pp. 115-122. https://doi.org/10.4334/IJCSM.2008.2.2.115
  9. Korea Concrete Institute (KCI) (2008), Design standard for concrete structures and commentary, Kimoondang, 523pp. (in Korean).
  10. Pam, H.J., Kwan, A.K.H., and Islam, M.S. (2001a), "Flexural Strength and Ductility of Reinforced Normal-and High-Strength Concrete Beams", Proceedings of the ICE-Structures and Buildings, Vol. 146, No. 4, pp. 381-389. https://doi.org/10.1680/stbu.2001.146.4.381
  11. Pam, H.J., Kwan, A.K.H., and Ho, J.C.M. (2001b), "Post-Peak Behavior and Flexural Ductility of Doubly Reinforced High- Strength Concrete Beams", Structural Engineering and Mechanics, Vol. 12, No. 5, pp. 459-74. https://doi.org/10.12989/sem.2001.12.5.459
  12. Park, R., and Paulay, T. (1975), Reinforced Concrete Structures. Wiely, New York, 769pp.
  13. Pendyala, R., Mendis, P., and Patnaikuni, I. (1996), "Full-Range Behavior of High-Strength Concrete Members: Comparison of Ductility Parameters of High and Normal-Strength Concrete Members", ACI Structural Journal, ACI. Vol. 93, No. 1, pp. 30-35.
  14. Rashid, M.A., and Mansur, M.A. (2005), "Reinforced High-Strength Concrete Beams in Flexure", ACI Structural Journal, ACI, Vol. 102, No. 3, pp. 462-471.

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