Use of Carbon Fibre Textile to Control Premature Failure of Reinforced Concrete Beams Strengthened with Bonded CFRP Plates

Abstract

The present study examines the performance of rectangular simply supported reinforced concrete (RC) beams with externally bonded reinforcement (EBR) made of carbon fibre-reinforced polymer (CFRP) plates. The load-carrying capacity of these CFRP EBR beams can be influenced by the strengthening of their ends, which controls the premature end failure occurring when the anchorage length of the plates or the shear span/depth ratio are low. Different basic techniques are proposed to prevent this brittle failure: use of clamps at the ends of the beam, bonding of lateral perpendicular or inclined strips and U-wrapping of shear spans with carbon fibre textile. The debonding mode of failure has systematically taken the place of the concrete cover separation mode. Lateral bonding of CFRP strips and U-wrapping using carbon fibre textile are particularly efficient for the control of debonding cracks and delay the premature end failure of the beams. The load-carrying capacity is enhanced, and the ductility is increased.

References

1. Triantafillou, T.C. and Plevris, N. (1992). Strengthening of RC Beams with Epoxy-Bonded Fibre-Composite Materials , Materials and Structures, 25(148): 201–211 .

2. Meier, U. (1995). Strengthening of Structures Using Carbon Fibre/Epoxy Composites , Construction and Building Materials, 9(6): 341–351 .

3. David, E., Djelal, C., Ragneau, E. and Buyle-Bodin, F. (1999). Use of FRP to Strengthen and Repair RC Beams: Experimental Study and Numerical Simulations , In: Proceedings of the 8th International Conference on Structural Faults and Repair, Engineering Technics Press, Edinburgh, CD.

4. Buyle-Bodin, F., David, E. and Ragneau, E. (2003). Finite Element Modelling of Flexural Behaviour of Externally Bonded CFRP Reinforced Concrete Structures , Engineering Structures, 24(11): 1423–1429 .

5. David, E., Ragneau, E. and Buyle-Bodin, F. (2003). Experimental Analysis of Flexural Behaviour of Externally Bonded CFRP Reinforced Concrete Structures , Materials and Structures, 36(258): 238–241 .

6. David, E. (1999). Comportement mecanique de poutres en beton arme renforcees ou reparees par collage de composite: etude experimentale et modelisation, PhD Thesis, Universite d’Artois, France.

7. Garden, H.N. and Hollaway, L.C. (1998). An Experimental Study of the Influence of Plate End Anchorage of Carbon Fibre Composite Plates Used to Strengthen Reinforced Concrete Beams , Composite Structures, 42(2): 175–188 .

8. Taljsten, B. (1997). Defining Anchor Lengths of Steel and CFRP Plates Bonded to Concrete , International Journal of Adhesion and Adhesives, 17(4): 319–327 .

9. Ritchie, P.A., Thomas, D.A., Lu, L.W. and Connely, G.M. (1991). External Reinforcement of Concrete Beams Using Fiber Reinforced Plastic , ACI Structural Journal, 88(4): 490–500 .

10.

10. Chaturvedi, S.K. and Zayas, R.A. (1998). Flexural Behaviour of Plain Concrete Beams Strengthened with Bonded Short-fiber Composite Strips , Journal of Advanced Materials, 30(4): 56–63 .

11.

11. Garden, H.N., Quantrill, R.J., Hollaway, L.C., Thorne, A.M. and Parke, G.A.R. (1998). An Experimental Study of the Anchorage Length of Carbon Fibre Composite Plates Used to Strengthen Reinforced Concrete Beams , Construction and Building Materials, 12(4): 203–219 .

12.

12. Sierra-Ruiz, V., Destrebecq, J-F. and Grediac, M. (2002). The Transfer Length in Concrete Structures Repaired with Composite Materials: A Survey of Some Analytical Models and Simplified Approaches , Composite Structures, 55(4): 445–454 .

13.

13. Hussain, M., Sharif, I., Basunbul, I.A., Baluch, M.H. and Al-Sulaimani, G.J. (1995). Flexural Behavior of Precracked Reinforced Concrete Beams Strengthened Externally by Steel Plates , ACI Structural Journal, 92(1): 14–22 .

14.

14. Sharif, I., Al-Sulaimani, G.J., Basunbul, I.A., Baluch, M.H. and Ghaleb, B.N. (1994). Strengthening of Initially Loaded Reinforced Concrete Beams Using FRP Plates , ACI Structural Journal, 91(2): 160–168 .

15.

15. Triantafillou, T.C. (1998). Shear Strengthening of Reinforced Concrete Beams Using Epoxy-bonded FRP Composites , ACI Structural Journal, 95(2): 107–115 .

16.

16. Khalifa, A. and Nanni, A. (2002). Rehabilitation of Rectangular Simply Supported RC Beams with Shear Deficiencies Using CFRP Composites , Construction and Building Materials, 16(3): 135–146 .

17.

17. Chajes, M.J., Januska, T.F., Mertz, D.R., Thomson, T.A. and Finch, W.W. (1995). Shear Strengthening of Reinforced Concrete Beams Using Externally Applied Composite Fabrics , ACI Structural Journal, 92(3): 295–303 .

18.

18. Taljsten, B. (2003). Strengthening Concrete Beams for Shear with CFRP Sheets , Construction and Building Materials, 17(1): 15–26 .

19.

19. Park, R. (1989). Evaluation of Ductility of Structures and Structural Assemblages from Laboratory Testing , Bulletin of the New Zealand National Society for Earthquake Engineering, 22(3): 155–166 .