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Ductile Strengthening of Reinforced Concrete Beams by Partially Unbonded NSM Hybrid FRP Rebars
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 Title & Authors
Ductile Strengthening of Reinforced Concrete Beams by Partially Unbonded NSM Hybrid FRP Rebars
Lee, Cha-Don; Chung, Sang-Mo; Won, Jong-Pil; Lee, Sng-Whan;
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 Abstract
New strengthening method based on Near Surface Mounted technique (NSM) is suggested, which can overcome the brittle nature of failure inherent to those reinforced concrete beams strengthened with FRP composite materials. The suggested technique secures ductile failure of reinforced concrete beams by having the strengthening Hybrid FRP rebars unbonded in parts. Experiments were performed in order to compare structural behaviors of strengthened beams with and without unbending along the Hybrid FRP rebars. Test results showed that only those beams strengthened by partially unbonded NSM failed in ductile manner. Theoretical expressions were derived for the minimum unbonded length of Hybrid FRP rebars with which ultimate strength of the reinforced concrete beam with partially unbonded NSM could be reached. The suggested partially unbonded NSM technique is expected to significantly improve the structural behavior of the strengthened beam with FRP composite materials.
 Keywords
ductile strengthening;experiments;structural performance;hybrid FRP rebars;reinforced concrete beams;
 Language
Korean
 Cited by
1.
CFRP Bar로 휨보강된 RC보의 단면확대공법에 의한 보강 효과에 대한 연구,김희성;장희석;이동운;

대한건축학회연합논문집, 2009. vol.11. 2, pp.187-194
 References
1.
Shahawy M., Chaallal O., Beitelman T.E. and Adna E.S., 'Flexural Strengthening with Carbon Fiber-Reinforced Polymer Composites of Preloaded Full-Scale Girders,' ACI Structural Journal. Vol.98,No.5, September-October 2001, pp.735-742

2.
Shin Y. S. and Lee C. D., 'Flexural Behavior of Reinforced Concrete Beams Strengthened with CFRP Laminates at Different Levels of Sustaining Load,'Accepted for publication in ACI Structural Journal

3.
Plevris N., Triantafillow T.C., and Veneziano D.,'Reliability of RC Members Strengthened with CFRP Laminates,' Journal of Structural Engineering, Vol.11, No.7, 1995, pp.1037-1044

4.
Arockiasamy M., Sowrirajan R., Shahawy M., and Beitelman T.E., 'Repair of Damaged Pretensioned Solid Slab Using CFRP Laminates,' Non-metallic (FRP) Reinforcement for Concrete Structures, Edited by Taerwe,L., Rilem, 1995, pp.492-500

5.
Saadatmanesh H. and Ehsani M. R., 'RC Beams Strengthened with GFRP Plates. I: Experimental Study,' Journal of Structural Engineering, Vol.117,No-11, November 1991, pp.3417-3433 crossref(new window)

6.
Saadatmanesh H. and Ehsani M.R., 'RC Beams Stre-ngthened with FRP Plates. II: Analysis and Parametric Study,' ASCE Journal of Structural Engineering, Vol.117, No.11, November 1991, pp.3434-3455 crossref(new window)

7.
Grace N. E., 'Continuous CFRP Prestressed Concrete bridges,' Concrete International, Oct. 1999, pp.42-47

8.
Alkhrdaji T., Nanni A., Chen G. and Barker M., 'Solid RC Decks Strengthened with FRP,' Concrete Inter-national, Oct. 1999, pp.31-41

9.
Lorenzis L. D. and Nanni A,'Strengthening of RC Structures with Near Surface Mounted. FRP Rods,' Report of Center for Infrastructure Engineering Studies, University of Missouri-Rolla, CIES 99-10, p.123

10.
Khalifa A., Alkhrdaji T., Nanni A., and Lansburg S.,'Anchorage of Surface Mounted FRP Reinforce-ment' Concrete International, Oct. 1999, pp.49-54

11.
Lees J. M. and Burgoyne C., 'Analysis of Concrete Beams with Partially Bonded Composite Reinforcement,' ACI Structural Journal, Vol.97, No.2, March-April 2000, pp.252-258

12.
Averston J. and Kelly A., 'Tensile First Crcking Strain and Strength of Hybrid Composites and Laminates;' Phil, London, 1980, A294, pp.519-534

13.
Tamuzs V., Tepfers R., Apinis R., and Modniks J., 'Pull-out, flexural rotation capacity and creep tests using hybrid composite rods and CFCC rods for reinforcement in concrete,' Institute of Polymer Mechanics Latian Academy of Sciences AizkrauMes 23, Riga, LV-1006 S-412 96, Latvia, Work No: 32,Publication: 99:4, 1999, pp.7-11

14.
Ehsani M R.; Saadatmanesh H; and Tao S., 'Design Recommendation for Bond of GFRP Rebars to Concrete,' Journal of Structural Engineering, Vol.122, No.3, 1996, pp.247-257 crossref(new window)

15.
Mattock A. H., 'Discussion of 'Rotational Capacity of Concrete Beams,' by W.Corley, Proceedings, ASCE, V.93, ST2, Apr.1967, pp.519-522

16.
Harajili M. H. and Hijazi S., 'Evaluation of the Ultimate Steel Stress in Unbonded Partially Prestressed Members,' Jounal, Precast/Prestressed oncrete Institute

17.
Park, Robert and Paulay, Thomas, Reinforced Ccncrete Structures, John Wiley & Sons, New York, 1975, p.769