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

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Shear Performance on SFRC Beam Using Recycled Coarse Aggregate

순환골재를 사용한 SFRC 보의 전단성능

  • Received : 2018.10.24
  • Accepted : 2018.10.29
  • Published : 2018.11.01
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Abstract

Degraded shear performance of reinforced concrete members with recycled coarse aggregate (RCA) compared to flexural strength is a problem. To address this, steel fibers can be used as concrete reinforcement material. In this study, the strength and deformation characteristics of SFRC beams using RCA were to be determined by shear tests. Major experimental variables include the volume fraction of steel fiber (0, 0.5%, 1%), the replacement rate of RCA (0%, 100%), and the shear span ratio (a/d = 1, 2). As a result of the experiment, the shear strength of the specimen increased as the rate of mixing steel fiber increased. For specimens with RCA and 1% steel fiber, the maximum shear strengths increased by 1.77 - 6.25% compared to specimens with normal coarse aggregate (NCA). On the other hand, at 0-0.5% steel fiber, the shear strengths of RCA specimens were reduced by 24.2% to 49.2% compared to NCA specimens. This indicates that reinforcement with 1% volume fraction of steel fiber greatly contributes to preventing shear strength reduction due to the use of RCA.

순환골재를 사용한 철근콘크리트 부재에서 휨강도에 비하여 전단성능 저하가 문제점으로 제기되고 있다. 이를 해결하기 위한 방법으로 강섬유를 콘크리트 보강재로 사용할 수 있다. 본 연구에서는 순환골재를 사용한 SFRC 보의 전단실험을 통하여 강도 및 변형 특성을 파악하고자 하였다. 주요 실험변수는 강섬유 혼입률(0, 0.5%, 1%), 순환골재 치환율(0%, 100%), 전단경간비(a/d = 1, 2) 등이다. 실험결과 실험에 의한 전단강도는 강섬유의 혼입률이 증가할수록 전단경간비가 작아질수록 증가하였다. 강섬유 1% 혼입한 순환골재의 경우 일반 골재에 비해 최대전단내력이 1.77~6.25% 증가한 반면에 강섬유 0~0.5% 혼입한 실험체에서는 일반골재에 비해 순환골재가 24.2%~49.2%의 전단강도가 저하되었다. 이를 볼 때 1% 강섬유 보강에 의하여 순환골재 사용에 따른 강도 저하를 방지하는데 크게 기여하는 것을 알 수 있다.

Keywords

References

  1. ACI Committee 544 (1988), Design Considerations for Steel Fiber Reinforced Concrete (ACI 544.4R-88), American Concrete Institute, Farmington Hills, Michigan, USA, 12-14.
  2. CSA Commitee A23.3 (2004), Design of Concrete Structures (CSA A23.3-04), Canadian Standards Association, Mississauga, Canada, 214.
  3. KCI2012 (2012), Korean Building Code, Korean Concrete Institute, Republic of Korea, 149-150.
  4. Kim, C. G., Park, H. G., Hong, G. H. and Kang, S. M. (2015), Evaluation on Shear Contribution of Steel Fiber Reinforced Concrete in Place of Minimum Shear Reinforcement, Journal of the Korea Concrete Institute, 27(6), 603-613. https://doi.org/10.4334/JKCI.2015.27.6.603
  5. Lee, J. H., Kim, W. S., Baek, S. M., Kang, Thomas H. K., and Kwak, Y. K. (2013), A Study on the Shear Behavior of Recycled Aggregate Reinforced Concrete Beams without Stirrups, Journal of the Korea Concrete Institute, 25(4), 389-400. https://doi.org/10.4334/JKCI.2013.25.4.389
  6. Lee, W. S., Yun, H. D., Kim, S. W., Choi, K. S., You, Y. C., and Kim, K. H. (2007), The Effect of Replacement Ratio of Recycled Coarse Aggregate on Shear Strength of Reinforced Concrete Beams Without Shear Reinforcement, Journal of the Architectural Institute of Korea Structure & Construction, 23(10), 3-10.
  7. Nam, J. W., Kim, H. J., Kim, S. B., Kim, J. H. Jay and Byun, K. J. (2007), Evaluations of Structural Performance of Recycled Aggregate Concrete According to Replacement Ratios, Journal of the Korean Recycled Construction Resources Institute, (4), 54-64.
  8. Narayanan, R., and Darwish, I. Y. S. (1987), Use of Steel Fibers as Shear Reinforcement, ACI Journal, 83(4), 216-227.
  9. Oh, Y. H., and Kim, J. H. (2008), Estimation of Flexural and Shear Strength for Steel Fiber Reinforced Flexural Members without Shear Reinforcements, Journal of the Korea Concrete Institute, 20(2), 257-267. https://doi.org/10.4334/JKCI.2008.20.2.257
  10. Romualdi, J. P., and Mandel, J. A. (1964), Tensile Strength of Concrete Affected by Uniformly Distributed and Closely Spaced Short Lengths of Wire Reinforcement, ACI Journal, 61(6), 657-671.
  11. Sharma, A. K. (1986), Shear Strength of Steel Fiber Reinforced Concrete Beams, ACI Journal, 83(4), 624-628.
  12. Shin, J. L., Kim, W. S., Baek, S. M., Kang, Thomas H. K., and Kwak, Y. K. (2015), Structural Performance Evaluation of Steel Fiber-Reinforced Concrete Beams with Recycled Coarse Aggregates, Journal of the Korea Concrete Institute, 27(3), 215-227. https://doi.org/10.4334/JKCI.2015.27.3.215
  13. Song, S. H., Choi, K. S., You, Y. C., Kim, K. H., and Yun, H. D. (2009), Flexural Behavior of Reinforced Recycled Aggregate Concrete Beams, Journal of the Korea Concrete Institute, 21(4), 431-439. https://doi.org/10.4334/JKCI.2009.21.4.431
  14. Zsutty, T. (1968), Beam Shear Strength Prediction by Analysis of Existing Data, ACI Journal, 65(11), 943-951.