고온노출된 강섬유보강 콘크리트의 인장성능에 대한 실험적 연구 = Experimental Study on Tensile Strength of Steel Fiber-Reinforced Concrete Subjected to High Temperature

국문 초록 (Abstract)

본 논문에서는 고온 노출된 강섬유 보강콘크리트의 인장성능을 실험적 연구를 통하여 검증하고자 하였다. 실험방법은 낮은 변동성을 특징으로 하는 DPT를 이용하였다. 일반적인 후크강섬유와 트위스트 강섬유, 0.25~1.0%의 강섬유 혼입률, 섬유형상비를 변수로 하여 실험을 수행하였다. 시험체는 고온 전기로에서 <TEX>$300^{\circ}C$</TEX>, <TEX>$500^{\circ}C$</TEX> 및 <TEX>$700^{\circ}C$</TEX>의 온도에서 2시간 노출되었으며, 12시간 동안 자연냉각 된 후에 가력되었다. 실험결과, 섬유혼입률이 증가할수록, 형상비가 클수록, DPT 인장강도가 증가하는 것으로 나타났다. 섬유종류의 영향은 다른 변수에 비하여 그 영향이 미미한 것으로 판단되었다. 실험결과를 근거로 강섬유의 혼입량과 형상비의 영향을 고려할 수 있는 노출온도 수준에 따른 DPT 인장강도 예측식을 제시하였다.

다국어 초록 (Multilingual Abstract)

Tensile strength of steel fiber-reinforced concrete was investigated with experimental program. For the investigation, Double Punch Test, which is known as a test method with low validity, was used. Fiber type(hooked and twisted fiber), mix ratios by volume ranged from 0.25% to 1.0%, aspect ratio were used as variables for the tests. The specimens were exposed to the elevated temperatures(<TEX>$300^{\circ}C$</TEX>, <TEX>$500^{\circ}C$</TEX> and <TEX>$700^{\circ}C$</TEX>) for 2 hours and placed at ambient temperatures for 12 hours before testing. Results demonstrated that residual tensile strength increases as mix ratio and aspect ratio increase. The effect of fiber type was insignificant. Based on the test results, the linear equation for prediction of DPT residual tensile strength was proposed in terms of mix ratio and aspect ratio.

참고문헌 (Reference)

1 문도영, "표준화재곡선을 이용한 잔존부착강도 평가 간략방법 제안" 한국방재학회 10 (10): 41-47, 2010

2 김동주, "비틀림 강섬유의 비틀림 횟수가 고성능 섬유보강 시멘트 복합재료의 인장거동에 미치는 영향" 한국콘크리트학회 22 (22): 575-583, 2010

3 김해수, "내화뿜칠된 콘크리트 충전 각형강관기둥의 내화성능" 한국방재학회 11 (11): 31-37, 2011

4 Chao, S.-H, "Use of Double Punch Test to Evaluate the Mechanical Performance of Fiber Reinforced Concrete"

5 Singh, S. P., "Strength and Flexural Toughness of Concrete Reinforced with Steel-Polypropylene Hybrid Fibers" 11 (11): 495-507, 2010

6 Shallal, D.M.A., "Strength and Elasticity of Steel Fiber Reinforced Concrete at High Temperatures" 11 (11): 125-133, 2007

7 Chen, B., "Residual strength of Hybrid-Fiber-Reinforced High-Strength Concrete after Exposure to High Temperature" 34 : 1065-1069, 2004

8 Balazs G, "Reinforced Concrete Structures in and after Fire" 72-80, 2012

9 김미혜, "RC 보의 충격저항성능 향상을 위한 강섬유 및 CFRP Sheet의 보강 효과" 한국방재학회 11 (11): 41-47, 2011

10 Khalil, L. W., "Influence of High Temperature on Steel Fiber Reinforced Concrete" 10 (10): 139-150, 2006

11 Alireza, J, "High Temperature Effect on Flexural Strength of Steel-Fibre Concrete" 1160-1167, 2008

12 Malatesta. S. C., "Generalization of the Barcelona test for the toughness control of FRC" 45 : 1053-1069, 2012

13 Jang, C. I., "Fire Resistance Performance for Fiber Reinforced High Strength Concrete Column Member" 20 (20): 457-460, 2008

14 Peng, G. -F., "Explosive spalling and residual mechanical properties of fiber-toughened high-performance concrete subjected to high temperatures" 36 : 723-727, 2006

15 Yan, Z.G., "Experimental study on mechanical behavior of tunnel lining under and after fire scenarios" 1805-1809, 2007

16 Lau, A., "Effect of high temperatures on high performance steel fibre reinforced concrete" 36 : 1698-1707, 2006

17 Chen, W. F., "Double Punch Test for Tensile Strength of Concrete" Fritz Laboratory 1969

18 Benard, E. S., "Correlations in Behavior of Fibre Reinforced Concrete Beam and Panel Specimens" 35 : 156-164, 2002

19 Chiaia, B., "Combining fiber-reinforced concrete with traditional reinforcement in tunnel linings" 31 : 1600-1606, 2009