An investigation on the flexural behaviour of RC beams wrapped with CFRP

Abstract

In addition to conventional retrofitting of constructions, new technologies are rapidly being developed to withstand the external effects while sustaining an acceptable level of damage. Reinforced concrete structures strengthened with fiber reinforced polymer composite materials are becoming more and more widespread in structural applications due to their better mechanical properties, resistance to environmental influences, ease of application and light weight, as well as conventional methods of strengthening. In this study, strengthening technique as a methodology for externally bonded with carbon fiber reinforced polymer (CFRP) sheets to increase the flexural resistance of reinforced concrete beams has been investigated. For this purpose, eight reinforced concrete beams were produced considering different types of CFRP configuration and tested under four-point bending loading. The dimensions of the beams are 150×250×2600 mm and concrete cover of the first and second group of test beam are 20 mm and 40 mm, respectively. Finally, load-deflection behavior with the failure mechanism of the tested beams have been discussed and the effect of different schemes of strengthening on the flexural behavior has been evaluated.

Keywords

• Carbon fiber reinforced polymer
• Flexural behavior
• RC beams
• Strengthening

References

1. 1. Tanarslan, H.M., Repairing and strengthening of earthquake damaged RC beams with CFRP strips. Magazine of Concrete Research, 2010. 62(5): p. 365-378.
2. 2. Niu, H. and Z. Wu, Numerical Analysis of Debonding Mechanisms in FRP-Strengthened RC Beams. Computer-Aided Civil and Infrastructure Engineering, 2005. 20(5): p. 354-368.
3. 3. Jankowiak, I., Analysis of RC Beams Strengthened by CFRP Strips-Experimental and FEA study. Archives of Civil and Mechanical Engineering, 2012. 12: p. 376-388.
4. 4. Dong, J., Q. Wang, and Z. Guan, Structural Behaviour of RC Beams with External Flexural and Flexural–shear Strengthening by FRP Sheets. Composites: Part B, 2013. 44: p. 604-612.
5. 5. Al-Rousan, R.Z., Effect of CFRP Schemes on the Flexural Behavior of RC beams Modeled by Using a Nonlinear Finite-element Analysis. Mechanics of Composite Materials, 2015. 51(4): p. 437-446.
6. 6. Ayaydın, M., İ. Dalyan and B. Doran. Nonlinear Analysis of RC Beams Wrapped with CFRP. in ICOCEE2018: Izmir. p. 1-12.
7. 7. ACI 440.2R-08, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. American Concrete Institute, 2008, U.S.A.
8. 8. Kotynia, R., Bond Between FRP and Concrete in Reinforced Concrete Beams Strengthened with Near Surface Mounted and Externally Bonded Reinforcement. Construction and Building Materials, 2012. 32: p. 41–54.

9. 9. Akram, A., R. Hameed, Z.A. Siddiqi, M.R. Riaz, and M. Ilyas, Finite Element Modeling of RC Beams Strengthened in Flexure using FRP Material. Arabian Journal for Science and Engineering, 2014. 39: p. 8573–8584.
10. 10. Siddiqui, N.A., Experimental Investigation of RC Beams Strengthened with Externally Bonded FRP Composites. Latin American Journal of Solids and Structures, 2009. 6: p. 343-362.
11. 11. Barris, C., L. Torres, A. Turon, M. Baena, and A. Catalan, An Experimental Study of the Flexural Behaviour of GFRP RC Beams and Comparison with Prediction Models. Composite Structures, 2009. 91: p. 286-295.
12. 12. Godat, A., Z. Qu, X.Z. Lu, P. Labossière, L.P. Ye, and K.W. Neale, Size Effects for Reinforced Concrete Beams Strengthened in Shear with CFRP Strips. Journal of Composites For Construction, 2010. 14(3): p. 260-271.
13. 13. Huang, J., Finite Element Modeling (FEM) of GFRP Bar Reinforced Concrete Beam: Flexural Behavior. Advanced Materials Research, 2011. Vols. 255-260: p. 3114-3118.
14. 14. Aktan, S., K. Polat, H.O. Köksal, B. Doran, and B. Deliktaş, Numerical Modeling for the Flexural Behaviour of Reinforced Concrete Beams Strengthened with FRP Sheets. in ACE 2014: İstanbul. p. 271-271.
15. 15. Nayak, A.N., A. Kumari, and R.B. Swain, Strengthening of RC Beams Using Externally Bonded Fibre Reinforced Polymer Composites. Structures, 2018. 14: p. 137-152.
16. 16. Toutanji, H., L. Zhao, and Y. Zhang, Flexural Behavior of Reinforced Concrete Beams Externally Strengthened with CFRP Sheets Bonded with an Inorganic Matrix. Engineering Structures, 2006. 28: p. 557-566.
17. 17. Al-Amery, R. and R. Al-Mahaidi, Coupled Flexural-Shear Retrofitting of RC Beams Using CFRP Straps. Composite Structures, 2006. 75: p. 457-464.
18. 18. Esfahani, M.R., M.R. Kianoush, and A.R. Tajari, Flexural Behaviour of Reinforced Concrete Beams Strengthened by CFRP Sheets. Engineering Structures, 2007. 29: p. 2428-2444.
19. 19. Reda, R.M., I.A. Sharaky, M. Ghanem, M.H. Seleem, and H.E.M. Sallam, Flexural Behaviour of RC Beams Strengtened by NSM GFRP Bars Having Different End Conditions. Composite Structures, 2016. 147: p. 131-142.
20. 20. Huang, L., L. Zhao and L. Yan, Flexural Performance of RC Beams Strengthened with Polyester FRP Composites. International Journal of Civil Engineering, 2018. 16: p. 715-724.
21. 21. Tahsiri, H., O. Semidi, A. Khaloo and E.M. Raisi, Experimental study of RC jacketed and CFRP strengthened RC beams. Construction and Building Materials, 2015. 95: p. 476-485.
22. 22. Mahal, M., B. Täljsten, and T. Blanksvärd, Experimental performance of RC beams strengthened with FRP materials under monotonic and fatigue loads. Construction and Building Materials, 2016. 122: p. 126-139.
23. 23. Sharaky, I.A., M. Baena, C. Barris, H.E.M. Sallam, and L. Torres, Effect of axial stiffness of NSM FRP reinforcement and concrete cover confinement on flexural behavior of strengthened RC beams:Experimental and numerical study. Engineering Structures, 2018. 173: p. 987-1001.
24. 24. Jawdhari, A., A. Peiris, and I. Harik, Experimental study on RC beams strengthened with CFRP rod panels. Engineering Structures, 2018. 39(5): p. 826-841.
25. 25. Dalyan, İ., Flexural Performance Evaluation of RC Beams Differently Strengthened with Fibre Reinforced Polymer. in Civil Engineering 2019, Yildiz Technical University: Turkey. p. 185. (in Turkish)
26. 26. Aram, M.R., C. Czaderski, and M. Motavalli, Debonding Failure Modes of Flexural FRP-Strengthened RC Beams. Composites Part B: Engineering, 2008. 39(5): p. 826-841.
27. 27. Oehlers, D.J., S.M. Park, and M.S. Mohamed Ali, A structural engineering approach to adhesive bonding longitudinal plates to RC beams and slabs. Composites: Part A: applied science and manufacturing, 2003. 34(2003): p. 887-897.
28. 28. Oehlers, D.J., P. Visintin, and W. Lucas, Flexural Strength and Ductility of FRP-Plated RC Beams: Fundamental Mechanics Incorporating Local and Global IC Debonding. Journal of Composites for Construction, 2016. 20(2): p. 1-13.
29. 29. Bhatti, A.Q. and N. Kishi, Control of FRP Debonding in Strengthened RC Beams. Arabian Journal for Science and Engineering, 2012. 37(8): p. 2103–2112.
30. 30. Wang, W-W., J-G. Dai and K.A. Harries, Intermediate crack-induced debonding in RC beams externally strengthened with prestressed FRP laminates. Journal of Reinforced Plastics and Composites, 2013. 32(23): p. 1842–1857.