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http://dx.doi.org/10.4334/JKCI.2003.15.1.017

Effects of Bar Deformation Height on Bond Degradation Subject to Cyclic loading  

Lee, Jae-Yuel (Dept. of Architectural Engineering, Soong-Sil University)
Kim, Byong-Kook (Dept. of Architectural Engineering, Soong-Sil University)
Hong, Gi-Suop (Dept. of Architecture, Hong-Ik University)
Choi, Oan-Chul (Dept. of Architecture, Hong-Ik University)
Publication Information
Journal of the Korea Concrete Institute / v.15, no.1, 2003 , pp. 17-24 More about this Journal
Abstract
One of the reasons for brittle failure in reinforced concrete structures subjected to severe earthquake is due to large local bond-slippage of bars resulting in fast bond degradation between reinforcing bars and concrete. This study aims to evaluate effects of bar deformation height on bond performance, specially, bond degradation under cyclic loading. Bond test specimens were constructed with machined bars with high relative rib areas. The degree of confinement by transverse bars is also another key parameters in this bond test. From test results, amounts of energy dissipation are calculated and compared for each parameter. Test results show that bond strength and stiffness drops significantly as cycles increases. The confinement and high relative rib area are effective to delay bond degradation, as the reduction of bond strength of cyclic loading compared to monotonic loading decreased for bars with large confinement and high relative rib areas. The energy dissipation also increases as the degree of confinement and relative rib area increases. However, tested bars with very high rib areas show that the bond may be damaged at relatively small slip because of high stiffness. The study will help to understand the bond degradation mechanism due to bar deformation height under cyclic loading and be useful to develop new deformed bars with high relative rib areas.
Keywords
bond degradation; confinement; cyclic load; deformation height; energy dissipation index;
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  • Reference
1 Michael L. Tholen and David Darwin., 'Effects of Deformation Properties on the Bond of Reinforcing Bars,' University of Kansas for Research, Lawrence,Kansas, 1996
2 Oan C. Choi, David Darwin, and Steven L. McCabe.,'Interface Characteristics for Bond of Reinforcing Steel to Concrete,' The Fourth East Asia-Pacific Conference on. Structural Engineering & Construction,Seoul, Korea, Sep., 1993, pp.751-756
3 ACI Committee 408, 'Splice and Development Length of High Relative Rib Area ReinforcingBars in Tension,' ACI International, 2001, Page 6
4 Darwin, D. and Nmai, C.K., 'Energy Dissipation in RC Beams under Cyclic Load,' J. Struc. Engrg.,ASCE, Vol.112, No.8, 1986, pp.1826-1846
5 David Darwin and E., Graham, 'Effect of Deformation Height and Spacing on Bond Strength of Reinforcing Bars,' ACI Structural Journal, Vo1.90, No.6 Nov-Dec,1993, pp.646-657
6 J Y. Lee., 'Bond Behauior of Deformed Bars Subjected to Cyclic Loading' Master Thesis, Soong Sil University, June., 2000, Page 69
7 J. Zuo and D Darwin., 'Bond Slip of High Relative Rib Area Bars under Cyclic Loading,' ACIStructural Journal, Vo1.97, No.2 , March-April, 2000,pp.331-334
8 Rolf Eligehausen, Egor P. Popov, Vitelmo V. Bertero.,'Loocil Bond Stress-Slip Relations of Deformed Bars Under Generalized Excitations,' Report No. UCB/EERC-83/23 Earthquake Engineering Research Center
9 최완철, 이재열, 이웅세, '반복하중시 철근마디형태에 따를 부착특성,' 한국콘크리트학회 논문집, 제3권 7호, 2001,pp.244-250
10 Tassios, T. R., 'Properties of bond Between Concrete and Steel Under Load Cycles Idealizing Seismic Actions,' Committee Euro-lnternational Du Beton,Bulletin No. 131, Paris, April, 1979