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The Effects of Steel-Fiber Reinforcement on High Strength Concrete Replaced with Recycled Coarse Aggregates More Than 60%

순환굵은골재 60% 이상 사용한 고강도 콘크리트에 대한 강섬유 보강 효과

  • Kim, Yoon-Il (Department of Architectural Engineering, Catholic Kwandong University)
  • 김윤일 (가톨릭관동대학교 건축공학과)
  • Received : 2016.11.18
  • Accepted : 2016.12.22
  • Published : 2016.12.30

Abstract

The purpose of this study is to examine the extent to which the deterioration in strength of high strength concrete of 60MPa replaced by a large amount of recycled coarse aggregates (more than 60% to 100% of replacement ratio) could be recovered with steel fiber reinforcement through material compressive strength test and shear failure test on short and middle beams and then to offer useful data for aggregate supply system of a sustainable resource circulation type. This study first examined the results of previous related tests. The results of the material compressive strength tests confirmed that when using a combination of steel fiber reinforcements of volumn ratio 0.75% and high quality recycled coarse aggregates with an water absorption rate within 2.0%, the strength characteristics of high strength concrete of 60MPa level were not only restored to the strength level of concrete made with natural aggregates, but also showed superior ductility. And the shear failure tests on short and middle beams using recycled coarse aggregates more than 60% with shear span to depth ratio (a/d) of 2 and 4 controlled by shear forces mainly confirmed that effects of superior shear strength increase and ductile behavior characteristics were showed by steel fiber reinforcements.

이 연구는 지속가능한 자원순환형 골재공급 시스템 구축에 유용한 자료 제공을 목적으로 하며, 순환굵은골재를 60% 이상 100%까지 다량 사용한 고강도 콘크리트에서 이로 인하여 나타나는 압축강도와 전단강도 저하가 강섬유 보강으로 어느 정도 회복되고 개선되는지를 재료시험과 보의 전단파괴 실험을 통하여 밝히고자 하는 것이다. 이 연구에서는 먼저 관련된 기존 실험연구 결과들을 고찰하였다. 재료시험 결과, 체적대비 0.75%의 강섬유 보강과 흡수율 2.0% 이내의 고품질 순환굵은골재를 병용하였을 때, 압축강도 60MPa 수준의 고강도콘크리트의 압축강도 특성이 천연골재 수준으로 회복되고 좋은 연성 특성이 나타나는 것을 확인하였다. 또한 전단력이 보 거동을 지배하는 전단스팬비(a/d) 2와 4인 보에 대한 전단파괴 실험에서 강섬유 보강에 의한 매우 큰 전단강도 증진 효과와 연성거동 특성을 확인하였다.

Keywords

References

  1. Ashour, S.A., Hasanain, G.S., Wafa, F.F. (1992). Shear behavior of high-strength fiber-reinforced concrete beams, ACI Structural Journal, 89(2), 176-184.
  2. Chung, H.S., Yang, K.H., Kim, H.H. (2006). The influence of the quality and the replacement level of recycled aggregate on the mechanical properties of concrete, Journal of the Architectural Institute of Korea, 22(6), 71-78 [in Korean].
  3. Ezeldin, S., Balaguru, P.N. (1997). Normal-and high-strength fiber-reinforced concrete under compression, ACI Material Journal, 94(4), 286-290.
  4. Fanella, D.A., Naaman, A.E. (1985). Stress-strain properties of fiber reinforced mortar in compression, ACI Journal, 82(4), 475-483.
  5. Jang, J.K., Lee, Y.J., Cho, B.H., Kim, Y.I. (2010). Strength deterioration of high-strength concrete using recycled aggregates and effects of steel-fiber reinforcement, The Regional Association of Architectural Institute of Korea Annual Conference of Collection Dissertations, 6(6), 533-536 [in Korean].
  6. Kwak, Y.K., Eberhard, M.O., Kim, W.S., Kim, J. (2002). Shear strength of steel fiber-reinforced concrete beams without stirrups, ACI Structural Journal, 99(4), 530-538.
  7. Kim, J.S., Shin, Y.S., Park, Y.B., Kim, J.H., Cho, C.H. (2008). A study on the structural characteristic of recycled aggregate concrete reinforced steel fiber, Journal of the Korea Institute of Building Construction, 8(5), 35-42 [in Korean] https://doi.org/10.5345/JKIC.2008.8.5.035
  8. Kim, Y.I., Lee, Y.K., Kim, M.S. (2008). Influence of steel fiber volume ratios on workability and strength characteristics of steel fiber reinforced high-strength concrete, Journal of the Korea Institute of Building Construction, 8(3), 75-83 [in Korean].
  9. Kim, Y.S., Yun, H.D., Byun, J.B., Choi, K.S., You, Y.C., Kim, K.H. (2008). Compressive behavior of recycled coarse aggregate concrete columns under uniaxial load, Journal of the Architectural Institute of Korea, 24(4), 75-82 [in Korean].
  10. Karl, K.W., Kim, K.S., Lee, D.H., Hwang, J.H., Ju, H.J., Seo, S.Y. (2010). An experimental study on shear strength of high-strength reinforced concrete beams with steel fibers, Journal of the Architectural Institute of Korea, 26(10), 19-28 [in Korean].
  11. Karl, K.W., Hwang, J.H., Lee, D.H., Park, H.C., Kim, K.S., Choi, I.S. (2011). Shear behavior of steel fiber-reinforced concrete at crack interfaces, Journal of the Architectural Institute of Korea, 27(12), 31-40 [in Korean]
  12. Kang, S.T., Ryu, G.S. (2011). The effect of steel-fiber contents on the compressive stress-strain relation of ultra-high performance cementitious composites(UHPCC), Journal of the Korea Concrete Istitute, 23(1), 67-75 [in Korean] https://doi.org/10.4334/JKCI.2011.23.1.067
  13. Kim, Y.C., Baek, S.M., Kim, W.S., Kang, Thomas H.K., Kwak, Y.K. (2014). An experimental study on flexural behavior of steel fiber reinforced concrete beams using recycled coarse, Journal of the Architectural Institute of Korea, 30(3), 39-48 [in Korean].
  14. Lee, W.S., Yun, H.D., Kim, S.W., Choi, K.S., You, Y.C., 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, 23(10), 3-10 [in Korean].
  15. Lee, M.J., Yun, H.D., Kim, S.W., Choi, K.S., You, Y.C., Kim, K.H. (2008). Bond performance between reinforcing bars and recycled coarse aggregate concrete with respect to reinforcement location, Journal of the Architectural Institute of Korea, 24(8), 29-39 [in Korean].
  16. Lee, Y.J., Jang, J.K., Kim, Y.I., Lim, C.S. (2010). "Using recycled aggregates in sustainable resource circulation system concrete for environment preservation," Spring Annual Conference, The Korean Institute of Building Construction, 10(1), 57-61 [in Korean].
  17. Lee, Y.J. (2011). Epidemiological Characteristics of High-Strength Concrete Using Recycled Aggregates and Effects of Steel-Fiber Reinforcement, Ph. D Thesis, Kwandong University [in Korean].
  18. Lee, B.C., Lee, J., Cho, Y.K., Jung, S.H. (2015). The strength and length change properties of recycled aggregate concrete(RAC) by compressive strength levels, The Korea Recycled Construction Resources Institute, 3(4), 307-312 [in Korean]. https://doi.org/10.14190/JRCR.2015.3.4.307
  19. Lee, H.H., Lee, T.W. (2016). Experimental study on mechanical properties and deformation behavior of concrete with recycled aggregates and steel fiber, Journal of the Korea Concrete Institute, 28(3), 257-363 [in Korean]. https://doi.org/10.4334/JKCI.2016.28.3.257
  20. Lim, W.Y., Hong, S.G. (2016). Compressive behavior of hybrid steel fiber reinforced ultra-high performance concrete, Journal of the Korea Concrete Institute, 28(2), 213-221 [in Korean]. https://doi.org/10.4334/JKCI.2016.28.2.213
  21. Narayanan, R., Darwish, I.Y.S. (1987). Use of steel fibers as shear reinforcement, ACI Structural Journal, 84(3), 216-227.
  22. Oh, Y.H. (2008). Evaluation of flexural strength for normal and high strength concrete with hooked steel fibers, Journal of the Korea Concrete Institute, 20(4), 531-539 [in Korean]. https://doi.org/10.4334/JKCI.2008.20.4.531
  23. Sharma, A.K. (1986). Shear strength of steel fiber reinforced concrete beams, ACI Journal, 83(4), 624-628.
  24. Song, P.S., Hwang, S. (2004). Mechanical properties of high-strength steel fiber-reinforced concrete, Construction and Building Materials, 18(9), 669-673 [in Korean]. https://doi.org/10.1016/j.conbuildmat.2004.04.027
  25. Song, S.H., Choi, K.S., You, Y.C., Kim, K.H., Yun, H.D. (2009). Flexural behavior of reinforced recycled aggregate concrete beams, Journal of the Korea Concrete Institute, 21(4), 431-439 [in Korean]. https://doi.org/10.4334/JKCI.2009.21.4.431
  26. Shin, J.L., Kim, W.S., Baek, S.M., Kang, Thomas H.K., 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 [in Korean]. https://doi.org/10.4334/JKCI.2015.27.3.215
  27. Shin, W.C., Lee, H.K., Baek, S.M,. Kim, W.S., Kwak, Y.K. (2016). An experimental study on the minimum reinforcement ratio of high strength reinforced concrete beams according to RCA replacement ratio, Journal of the Architectural Institute of Korea, 32(10), 13-22 [in Korean].
  28. Williamson, G.R. (1974). The Effect of Steel Fiber on the Compressive Strength of Concrete, in Fiber Reinforced Concrete, American Concrete Institute, SP-44, 195-208.
  29. Zsutty, T.C. (1971). Shear strength prediction for separate categories of simple beam test, ACI Journal, 68(2), 138-143.