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고속충격하중을 받는 강섬유보강콘크리트 패널의 내충격성능

Impact Resistance of Steel Fiber-Reinforced Concrete Panels Under High Velocity Impact-Load

  • Kim, Sang-Hee (Dept. of Architecture and Architectural Engineering, Seoul National University) ;
  • Kang, Thomas H.K. (Dept. of Architecture and Architectural Engineering, Seoul National University) ;
  • Hong, Sung-Gul (Dept. of Architecture and Architectural Engineering, Seoul National University) ;
  • Kim, Gyu-Yong (Dept. of Architectural Engineering, Chungnam National University) ;
  • Yun, Hyun-Do (Dept. of Architectural Engineering, Chungnam National University)
  • 투고 : 2014.06.27
  • 심사 : 2014.10.14
  • 발행 : 2014.12.31

초록

본 실험적 연구는 고속 비상체에 의한 강섬유보강콘크리트의 내충격성을 파악하는데 그 목적이 있다. 이 연구에서는 패널두께 대 탄환지름 비가 3.5 이하인 패널 실험체에 강섬유 혼입률, 패널 두께, 충격 속도, 골재 크기를 변수로 조절하면서 고속충격을 가하여서 실험체의 성능을 비교하였다. 강섬유 혼입률이 증가할수록 중량손실량 및 표면 탈락률은 감소하지만, 관입깊이는 증가하는 추세를 보였다. 그리고 충격하중을 받을 때의 거동은 골재 20 mm를 사용하였을 경우 더욱 불리하게 나타났다. 실험결과는 기존 모델에 의한 예측값과 비교하였고, 이를 통해 패널두께 대 탄환지름 비가 3.5 이하일 때 보수적인 예측을 하는것을 확인하였다. 이 중 수정 NDRC 제안식과 ACE 제안식이 Hughes 제안식보다 안정되게 예측하는 것으로 나타났다. 관입깊이와 배면박리한계두께에 있어서는 강섬유 혼입률에 따라서 예측식과 오차가 크게 나타나기도 하지만, 관통깊이는 수정 NDRC 제안식 및 Hughes 제안식에 의해 비교적 정확하게 예측되었다.

This paper describes the evaluation of the impact performance of steel fiber-reinforced concrete based on high-velocity impact experiments using hard spherical balls. In this experimental study, panel specimens with panel thickness to ball diameter (h/d) ratios of 3.5 or less were tested with variables of steel fiber volume fraction, panel thickness, impact velocity, and aggregate size. Test results were compared with each other to evaluate the impact resistance. The results showed that the percentage of weight and surface loss decreased as the steel volume fraction increased. However, the penetration depth increased with up to steel fiber volume fraction of 1.5%. Particularly the results of specimens with 20 mm aggregates showed poorer performance than those with 8 mm aggregates. The results also confirmed that the impact performance prediction formulas are conservative with (h/d) ratios of 3.5 or less. Despite the conservative predictions, the modified NDRC formula and ACE formula predict the impact performance more consistently than the Hughes formula.

키워드

참고문헌

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피인용 문헌

  1. High-Velocity Impact Experiment on Impact Resistance of Steel Fiber-Reinforced Concrete Panels with Wire Mesh vol.27, pp.2, 2015, https://doi.org/10.4334/JKCI.2015.27.2.103
  2. Face Damage Characteristic of Steel Fiber-Reinforced Concrete Panels under High-Velocity Globular Projectile Impact vol.27, pp.4, 2015, https://doi.org/10.4334/JKCI.2015.27.4.411