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Bond-Strengthening Hooks for RC Members with High Strength Spirals
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 Title & Authors
Bond-Strengthening Hooks for RC Members with High Strength Spirals
Kim Kil-Hee; Sato Yuichi;
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This paper presents an experimental investigation of bond-strengthening hooks as a new method to increase bond strength along flexural reinforcing bars in reinforced concrete (RC) beams and columns. The RC members, which consisted of 1,300 MPa-class spirals as shear reinforcement, often suffered from bond splitting failure. The proposed method attempts to increase confining stiffness around the flexural bars by placing U-shaped hooks and to prevent premature bond splitting failure. Twelve specimens with varied amounts and sizes of the hooks were prepared to verify the strengthening effectiveness under monotonic and cyclic loading conditions. The test result indicated that the hooks increased the bond strength along the flexural bars although the strengthening effectiveness was limited by effective reinforcement ratio . This limit is determined by size of stress-transmitting zones of concrete around anchors of the hooks. Anchors of the hooks are recommended to be longer than twelve times the hook diameter and inserted deeper than a quarter of the member depth (D/4). Proposed design equations provide modest estimates of the shear strengths.
beam;column;shear strength;bond strength;hook;high strength spirals;
 Cited by
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한국구조물진단유지관리공학회 논문집, 2010. vol.14. 5, pp.102-109
고강도 전단철근을 사용한 철근콘크리트 보의 부착성능 향상에 관한 실험적 연구,김상우;김도진;윤혜선;백승철;김길희;

한국콘크리트학회논문집, 2010. vol.22. 4, pp.527-534 crossref(new window)
콘크리트 압축강도에 따른 고강도 나선철근의 횡구속 효과,김상우;김영식;윤군진;이정윤;김길희;

한국구조물진단유지관리공학회 논문집, 2012. vol.16. 4, pp.89-98 crossref(new window)
Experimental Study on Improvement of Bond Performance of RC Beams with High-Strength Shear Reinforcement, Journal of the Korea Concrete Institute, 2010, 22, 4, 527  crossref(new windwow)
Confinement Effect of High-Strength Steel Spirals According to Compressive Strength of Concrete, Journal of the Korea institute for structural maintenance and inspection, 2012, 16, 4, 89  crossref(new windwow)
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