Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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Seismic Performance Assessment of Roof-Level Joints with Steel Fiber-Reinforced High-Strength Concrete

강섬유보강 고강도콘크리트를 적용한 최상층 접합부의 내진성능 평가

  • Kim, Sang-Hee (Dept. of Architecture and Architectural Engineering, Seoul National University) ;
  • Kwon, Byung-Un (Dept. of Architecture and Architectural Engineering, Seoul National University) ;
  • Kang, Thomas H.-K. (Dept. of Architecture and Architectural Engineering, Seoul National University)
  • Received : 2015.12.17
  • Accepted : 2016.03.21
  • Published : 2016.04.30
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Abstract

This study was conducted to verify seismic performance of special moment frame's joints at roof-level with high-strength concrete and SD600 bars. K-RC-H was designed according to the seismic code and K-HPFRC-H had 150% of the original hoop spacing and 1.0% steel fiber volume fraction compared with K-RC-H. Both specimens had remarkable seismic performance without noticeable decrease in moment, but with very good energy dissipation before rebar failure. The U-bars in the joint sufficiently constrained rebar's action that pushed the cover upward. SD600 bars with $1.25l_{dt}$ had minimum slip in the joint. It was considered that the steel fiber contributed to improvement of the bending moment and joint shear distortion, and the result showed that it would be possible to increase the hoop spacing to 150% of the regular spacing.

본 논문에서는 고강도콘크리트와 SD600 철근을 적용한 특수모멘트골조의 최상층 접합부 내진성능을 파악하고자 한다. 실험체 중 K-RC-H는 내진규정에 따라 제작되었으며, K-HPFRC-H에는 횡보강근 간격을 150%로 증가시키면서 대신 강섬유를 부피비 1.0% 혼입하였다. K-RC-H, K-HPFRC-H 실험체 모두 주근이 파단하기 이전까지 내력 저하가 거의 없었고 에너지 소산능력 등에서 우수한 내진성능을 보였다. 접합부내의 U-bar는 보 주근이 휨과 함께 인장력을 받을 때 상부면으로 밀어내려는 현상을 충분히 억제하는 것으로 나타났다. 한편 SD600의 정착길이는 $1.25l_{dt}$가 확보되었는데 슬립거동이 거의 발생하지 않았다. 전반적으로 강섬유의 혼입은 휨강도 증가, 전단변형각 구속력 향상 등에 기여하였고, 강섬유 혼입률 1.0% 혼입함으로써 횡보강근 간격을 1.5배 증가시킬 수 있는 가능성을 실험적으로 확인하였다.

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References

  1. Architectural Institute of Korea, Korean Building Code and Commentary 2009, Kimoondang Publishing Company, Korea, 2009, p.1040 (in Korean).
  2. ACI Committe 318, Building Code Requirements for Structural Concrete and Commentary (ACI 318-11), American Concrete Istitute, 2011.
  3. Korea Concrete Institute, Design Code for Concrete Structures, KCI, 2012, p.599 (in Korean).
  4. ACI-ASCE Committe 352, Recommendations for Design of Beam-Column Joints in Monolithic Reinforced Concrete Structures (ACI 352R-02), American Concrete Institute, 2002, p.38.
  5. Chun, S. C., and Lee, J.-G., "Strengths of Lap Splices Anchored by SD 600 Headed Bars", Journal of the Korea Concrete Institute, Vol.25, No.2, 2013, pp.217-224 (in Korean). https://doi.org/10.4334/JKCI.2013.25.2.217
  6. Kim, W., Experimental Analysis for Steel Congestion Relief in Concrete Structures under Monotonic and Seismic loads, PhD thesis, University of Oklahoma, 2011.
  7. Hwang, H.-J., Park, H.-G., Choi, W.-S., Chung, L., and Kim, J.-K., "Seismic Performance of Beam-Column Connections for Special Moment Frame Using 600MPa Flexural Reinforcement", Journal of the Korea Concrete Institute, Vol.23, No.5, 2011, pp.591-601 (in Korean). https://doi.org/10.4334/JKCI.2011.23.5.591
  8. Chun, S. C., Lee, S. H., Kang, T. H.-K., Oh, B., and Wallace, J. W., "Mechanical Anchorage in Exterior Beam- Column Joints Subjected to Cyclic Loading", ACI Structural Journal, Vol.104, No.1, 2007, pp.102-112.
  9. Park, J. J., Ryu, G. S., Kang, S. T., An, G. H., Koh, G. T., and Kim, S. W., "An Experimental Study on Viscosity of UHPC according to Silica Fume Type", Proceeding of KCI 2011 Spring Convention, Vol.23, No.1, 2011, pp.427-428 (in Korean).
  10. ACI Committee 374, Guide for Testing Reinforced Concrete Structural Elements under slowly Applied Simulated Seismic Loads (ACI 374.2R-13), American Concrete Institute, 2013.
  11. Ahn, K.-L., Jang, S.-J., Jang, S.-H., and Yun H.-D., "Effects of Aggregate Size and Steel Fiber Volume Fraction on Compressive Behaviors of High-Stregnth Concrete", Journal of the Korea Concrete institute, Vol.27, No.3, 2015, pp. 228-235 (in Korean).
  12. Angelakos, B., The Behavior of Reinforced Concrete Knee Joints under Earthquake Loads, PhD thesis, University of Toronto, 1999.
  13. ACI Committee 544, Design Considerations for Steel Fiber Reinforced Concrete (ACI 544.4R-88 (Reapproved 2009)), American Concrete Institute, 1988.
  14. Megget, L. M., "The Seismic Design and Performance of Reinforced Concrete Beam-Column Knee Joints in Buildings", Earthquake Spectra, Vol.19, No.4, 2003, pp.863-895. https://doi.org/10.1193/1.1623782
  15. Jindal, R., and Sharma, V., "Behavior of Steel Fiber Reinforced Concrete Knee-Type Beam-Column Connections", Fiber Reinforced properties and Applications, SP-105, American Concrete Institute, 1987, pp.475-491.
  16. Pantazopoulou, S. and Bonacci, J., "Consideration of Questions about Beam-Column Joints", ACI Structural Journal, Vol.89, No.1, 1992, pp.27-36.