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Direct Punching Shear Strength Model for Interior Slab-Column Connections and Column Footings with Shear Reinforcement

전단 보강 슬래브-기둥 내부 접합부 및 기초판에 대한 뚫림 전단강도 모델

  • Received : 2010.08.27
  • Accepted : 2010.11.22
  • Published : 2011.04.30

Abstract

In the present study, an improved design method was developed for the punching shear strength of interior slabcolumn connections and column footings with and without shear reinforcement. In the evaluation of the punching shear strength, the possible failure mechanisms of the connections and column footings were considered. The considered failures modes were inclined tensile cracking of concrete, yielding of shear re-bars, and concrete crushing of compression zone/strut. The punching shear applied to the concrete critical section was assumed to be resisted mainly by the compression zone. The punching shear strength of the concrete compression zone was evaluated based on the material failure criteria of the concrete subjected to the compressive normal stress and shear stress. For verification of the proposed design method, its prediction was compared with the existing test results. The result showed that the proposed method predicted the strengths of the test specimens better than the current design methods of the KCI code for both the shear reinforced and unreinforced cases.

이 연구에서는 뚫림 전단을 재하받는 전단 보강/전단 무보강 슬래브-기둥 내부 접합부와 기초판에 대하여 개선된 설계 방법을 개발하였다. 슬래브-기둥 접합부와 기초판의 다양한 파괴 메커니즘(경사 인장 균열 파괴, 전단 보강근의 항복, 콘크리트 압축대/스트럿의 압축 파괴)을 고려하여 뚫림 전단강도를 산정하였다. 콘크리트 위험 단면에 작용하는 뚫림 전단은 대부분 콘크리트 압축대에 의하여 지지된다고 가정하였으며, 콘크리트 압축대의 뚫림 전단강도는 압축 수직 및 전단의 조합 응력을 재하받는 콘크리트 재료 파괴 기준에 근거하여 산정하였다. 제안된 강도 모델은 실험 결과 와의 비교를 통하여 검증하였다. 검증 결과, 제안된 설계 방법은 전단 보강 및 전단 무보강 경우에 대하여 현행 KCI 설계기준 보다 우수한 강도 추정 능력을 가지고 있다는 점이 밝혀졌다.

Keywords

References

  1. MacGregor, J. G. and Wight, J. K., Reinforced Concrete: Mechanics and Design, Prentice Hall, NJ, 2005, 1132 pp.
  2. 동부건설, 미래형 아파트 구조시스템 개발에 관한 연구, 2003, pp. 285-286
  3. Ruiz, M. F. and Muttoni, A., “Applications of Critical Shear Crack Theory to Punching of Reinforced Concrete Slabs with Transverse Reinforcement.” ACI Struct. J., 106-S46, 2009, pp. 485-494
  4. Beutel, R. and Hegger, J., Punching Shear Resistance of Shear Reinforced Flat Slabs, Arbeitsgemeinshaft industrieller Forschungsvereinigungen “Otto von Guericke” e. V., Research Programm Nr.10644-N, DBV 185, 1998.
  5. Pralong, J., Poinconnement Symetrique des Plachers-Dalles, IBK-Bericht Nr. 131, Insitut fur Baustatik und Konstruktion ETH Zurish, 1982.
  6. Johansen, K. W., Yield-Line Theory, Cement and Concrete Ass., London, 1962, 181 pp.
  7. 최경규, 박홍근, “플랫플레이트-기둥 접합부의 뚫림 전단 강도,” 콘크리트학회 논문집, 16권, 2호, 2004, pp. 163-174.
  8. ACI Committee 318, Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary (ACI 318R-08), USA, 2008, 473 pp.
  9. 한국콘크리트학회, 콘크리트 구조설계기준 해설, 2007, 524 pp.
  10. EC 2, Design of Concrete Structures Part I: General Rules and Rules for Buildings, European Committee for Standardization Brussels, 2002, 225 pp.
  11. FIP 12, Punching of Structural Concrete Slabs, CEB-FIP Task Group, Lausanne, Switzerland, 2001, 314 pp.
  12. Park, H. and Choi, K., “Improved Strength Model for Interior Flat Plate-Column Connections Subject to Unbalanced Moment,” ASCE J. Structural Engr., Vol. 132, No. 5, 2006, pp. 694-704. https://doi.org/10.1061/(ASCE)0733-9445(2006)132:5(694)
  13. Hegger, J., Ricker, M., and Sherif, A. G., “Punching Strength of Reinforced Concrete Footings,” ACI Structural Journal, Vol. 106, No. 5, 2009, pp. 706-715.
  14. 최경규, 박홍근, “무량판 슬래브-기둥 접합부에 대한 전 단강도 모델,” 콘크리트학회 논문집, 22권, 3호, 2010, pp. 345-356. https://doi.org/10.4334/JKCI.2010.22.3.345
  15. Kotsovos, M. D. and Pavlovic, M. N., “Ultimate Limit-State Design of Concrete Structures,” a New Approach, Thomas Telford, London, 1998, 208 pp.
  16. Zararis, P. D. and Papadakis, G. C., “Diagonal Shear Failure and Size Effect in RC Beams without Web Reinforcement,” J. Struct. Engrg., ASCE, Vol. 127, No. 7, 2001, pp. 733-742. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:7(733)
  17. Jelic, I., Pavlovic, M. N., and Kotsovos, M. D., A “Study of Dowel Action in Reinforced Concrete Beams,” Magazine of Concrete Research, Vol. 51, No. 2, 1999, pp. 131-141. https://doi.org/10.1680/macr.1999.51.2.131
  18. Tureyen, A. K. and Frosch, R. J., “Concrete Shear Strength, Another Perspective,” ACI Struct. J., Vol. 100, No. 5, 2003, pp. 609-615.
  19. Choi, K., Park, H., and Wight, J. K., “Unified Shear Strength Model for Reinforced Concrete Beams-Part I: Development,” ACI Struct. J., Vol. 104, No. 2, 2007, pp. 142-152.
  20. Choi, K., Reda Taha, M. M., Park, H., and Maji, A. K., “Punching Shear Strength of Interior Concrete Slab-Column Connections Reinforced with Steel Fibers,” Cement and Concrete Composites, Vol. 29, No. 5, 2007, pp. 409-420. https://doi.org/10.1016/j.cemconcomp.2006.12.003
  21. Park, H., Choi, K., and Wight, J. K., “Strain-Based Shear Strength Model for Slender Beams without Web Reinforcement,” ACI Struct. J., Vol. 103, No. 6, 2006, pp. 783-793.
  22. Chen W. F., Plasticity in Reinforced Concrete, NewYork, McGraw-Hill, 1982, pp. 204-205.
  23. CSA A23.3-M04 Technical Committee, Design of Concrete Structures, Canadian Standards Associations, Toronto, Ontario, 2004, 258 pp.
  24. Kinnunen, S. and Nylander, H., “Punching of Concrete Slabs without Shear Reinforcement,” Transactions No. 158, Royal Institute of Technology, Stockholm, 1960, 112 pp.
  25. Bažnt, Z. P. and Cao, Z., “Size Effect in Punching Shear Failure of Slabs,” ACI Struct. J., Vol. 84, No. 1, 1987, pp. 44-53.
  26. Manterola, M., “Poinconnement de Dalles Sans Armature D’effort Trenchant,” Comite Europeen du Beton (Hrsg.), Dalles, Structures Planes, CEB-Bull, Paris, D’Information 1966, 58 pp.
  27. Beutel, R., “Punching of Flat Slabs with Shear Reinforcement at Inner Columns,” Rheinisch-Westfalischen Technischen Hochschule Aachen, Aachen, Germany, 2002, 267 pp.
  28. Shehata, I. A. E. M., “Theory of Punching in r. c. Slabs,” Ph.D, Thesis, Polytechnic of Central London, 1985.
  29. Sherif, A. G. and Dilger, W. H., “Tests of Full-Scale Continuous Reinforced Concrete Flat Slabs,” ACI Struct. J., Vol. 97, No. 3, 2000, pp. 455-467.
  30. Mokhtar, A., Ghali, A., and Dilger, W. H., “Stud Shear Reinforcement for Flat Concrete Plates,” ACI J., Vol. 82, No. 5, 1985, pp. 676-683.
  31. Pilakoutas, K. and Li, X., “Alternative Shear Reinforcement for Reinforced Concrete Flat Slabs,” ASCE, Vol. 129, No. 9, 2003, pp. 1164-1172. https://doi.org/10.1061/(ASCE)0733-9445(2003)129:9(1164)
  32. Adetta, B. and Polak, M. A., “Retrofit of Slab Column Interior Connections Using Shear Boltss,” ACI Struct. J., Vol. 102, No. 2, 2005, pp. 268-274.
  33. Langohr, P. H., Ghali, A., and Dilger, W. H., “Special Shear Reinforcement for Concrete Flat Plate,” ACI Journal, Vol. 73, No. 3, 1976, pp. 141-146.
  34. Seible, F., Ghali, A., and Dilger, W. H., “Preassembled Shear Reinforcing Units for Flat Plates,” ACI Journal, Vol. 77, No. 1, 1980, pp. 28-35.
  35. Vam der Voet, A. F., Dilger, W. H., and Ghali, A., “Concrete Flat Plates with Well-Anchored Shear Reinforcement Elements,” Canadian Journal of Civil Engineering, Vol. 9, No. 1, 1982, pp. 107-114. https://doi.org/10.1139/l82-011
  36. Broms, C. E., “Shear Reinforcement For Deflection Ductility of Flat Plates,” ACI Struct. J., Vol. 87, No. 6, 1990, pp. 696-705.
  37. Hegger, J., Sherif, A. G., and Ricker, M., “Experimental Investigations on Punching Behavior of Reinforced Concrete Foooting,” ACI Structural Journal, Vol. 103, No. 4, 2006, pp. 604-612.
  38. Richart, F. E., “Reinforced Concrete Wall and Column Footings Part 1,” J. of ACI, Vol. 20, No. 2 1948, pp. 97-127.

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