Intermediate crack-induced debonding analysis for RC beams strengthened with FRP plates

- Journal title : Structural Engineering and Mechanics
- Volume 56, Issue 3, 2015, pp.473-490
- Publisher : Techno-Press
- DOI : 10.12989/sem.2015.56.3.473

Title & Authors

Intermediate crack-induced debonding analysis for RC beams strengthened with FRP plates

Wantanasiri, Peelak; Lenwari, Akhrawat;

Wantanasiri, Peelak; Lenwari, Akhrawat;

Abstract

This paper presents the analysis of intermediate crack-induced (IC) debonding failure loads for reinforced concrete (RC) beams strengthened with adhesively-bonded fiber-reinforced polymer (FRP) plates or sheets. The analysis consists of the energy release and simple ACI methods. In the energy release method, a fracture criterion is employed to predict the debonding loads. The interfacial fracture energy that indicates the resistance to debonding is related to the bond-slip relationships obtained from the shear test of FRP-to-concrete bonded joints. The section analysis that considers the effect of concrete`s tension stiffening is employed to develop the moment-curvature relationships of the FRP-strengthened sections. In the ACI method, the onset of debonding is assumed when the FRP strain reaches the debonding strain limit. The tension stiffening effect is neglected in developing a moment-curvature relationship. For a comparison purpose, both methods are used to numerically investigate the effects of relevant parameters on the IC debonding failure loads. The results show that the debonding failure load generally increases as the concrete compressive strength, FRP reinforcement ratio, FRP elastic modulus and steel reinforcement ratio increase.

Keywords

fiber-reinforced polymers;strengthening;reinforced concrete beams;intermediate crack-induced debonding;bond-slip relationships;fracture mechanics;

Language

English

References

1.

Achinta, P.M.M. and Burgoyne, C.J. (2008), "Fracture mechanics of plate debonding", J. Compos. Constr., 12(4), 396-404.

2.

Achinta, P.M.M. (2009), "Fracture analysis of debonding mechanism for FRP plates", Ph.D. Dissertation, University of Cambridge, Cambridge.

3.

ACI Committee 440 (2008), Guide for Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-08), American Concrete Institute, Michigan.

4.

Beber, A.J., Campos Filho, A. and Campagnolo, J.L. (1999), "Flexural strengthening of R/C beams with CFRP sheets", Proceedings of 8th International Structural Faults and Repair Conference, London.

5.

Chan, T.K., Cheong, H.K. and Nguyen, D.M. (2001), "Experimental investigation on delamination failure of CFRP strengthened beams", Proceedings of ICCMC/IBST 2001 International Conference on Advanced Technologies in Design, Construction and Maintenance of Concrete Structures, Hanoi, March.

6.

Choi, E., Utui, N. and Kim, H.S. (2013), "Experimental and analytical investigations on debonding of hybrid FRPs for flexural strengthening of RC beams", Compos. Part B-Eng., 45, 248-256.

7.

Dai, J.G., Harries, K.A. and Yokota, H. (2008), "A critical steel yielding length model for predicting intermediate crack-induced debonding in FRP-strengthened RC members", Steel Compos. Struct., 8(6), 457-473.

8.

Dai. J.G., Ueda, T. and Sato, Y. (2005), "Development of the nonlinear bond stress-slip model of fiber reinforced plastics sheet-concrete interfaces with a simple method", J. Compos. Constr., 9(1), 52-62.

9.

Fanning, P.J. and Kelly, O. (2001), "Ultimate response of RC beams strengthened with CFRP plates", J. Compos. Constr., 5(2), 122-127.

10.

Gao, B., Kim, J.K. and Leung, C.Y.K. (2004), "Experimental study on RC beams with FRP strips bonded with rubber modified resins", Compos. Sci. Technol., 64, 2557-2564.

11.

Guan, G.X., Burgoyne, C.J. and Achintha, M. (2014), "Parametric study of FRP plate debonding using global energy balance", J. Compos. Constr., 18(6), 04014020.

12.

Gunes, O. (2004), "A fracture based approach to understanding debonding in FRP bonded structural members", Ph.D. Dissertation, Massachusetts Institute of Technology, Massachusetts.

13.

Gunes, O., Buyukozturk, O. and Karaca E. (2009), "A fracture-based model for FRP debonding in strengthened beams", Eng. Fract. Mech., 76, 1897-1909.

14.

Hao, S.W., Liu, Y. and Liu X.D. (2012), "Improved interfacial stress analysis of a plated beam", Struct.Eng. Mech, 44(6), 815-837.

15.

Kishi, N., Mikami, H., Sato, M. and Matsoka, K. (1998), "Flexural bond behavior of RC beams externally bonded with FRP sheets", Proceedings of the Japan Concrete Institute, 20(1), 515-520.

16.

Lenwari, A., Thepchatri, T. and Albrecht, P. (2005), "Flexural response of steel beams strengthened with partial-length CFRP plates", J. Compos. Constr., 9(4), 296-303.

17.

Lenwari, A. and Thepchatri, T. (2009), "Experimental study on RC beams strengthened with carbon and glass fiber sheets", Eng. J., 13(2), 9-18.

18.

Leung, C.K.Y. (2001), "Delamination failure in concrete beams retrofitted with a bonded plate", J. Mater. Civil Eng., 13, 106-113.

19.

Liu, I.S.T., Oehlers, D.J. and Seracino, R. (2007), "Study of intermediate crack debonding in adhesively plated beams", J. Compos. Constr., 11(2), 175-183.

20.

Lu, X.Z., Teng, J.G., Ye, L.P. and Jiang, J.J. (2007), "Intermediate crack debonding in FRP-strengthened RC beams: FE analysis and strength model", J. Compos. Constr., 11(2), 161-174.

21.

Maalej, M. and Leong, K.S. (2005), "Effect of beam size and FRP thickness on interfacial shear stress concentration and failure mode of FRP-strengthened beams", Compos. Sci. Technol., 65, 1148-1158.

22.

Malek, A.M., Saadatmanesh, H. and Ehsani, M.R. (1998), "Prediction of failure load of R/C beams strengthened with FRP plate due to stress concentration at the plate end", ACI Struct. J., 95(1), 142-152.

23.

Nakaba, K., Kanakubo, T., Furuta, T. and Yoshizawa, H. (2001), "Bond behavior between fiber-reinforced polymer laminates and concrete", ACI Struct. J., 98(3), 359-367.

24.

Ombres, L. (2010), "Prediction of intermediate crack debonding failure in FRP-strengthened reinforced concrete beams", Compos. Struct., 92, 322-329.

25.

Park, R. and Paulay, T. (1975), Reinforced Concrete Structures, John Wiley & Sons, New York.

26.

Rahimi, H. and Hutchinson, A. (2001), "Concrete beams with externally bonded FRP plates", J. Compos. Constr., 5(1), 44-56.

27.

Saadatmanesh, H. and Ehsani, M.R. (1991), "RC beams strengthened with GFRP plates I: experimental study", J. Struct. Eng., 117(11), 3417-3433.

28.

Said, H. and Wu, Z. (2008), "Evaluating and proposing models of predicting IC debonding failure", J. Compos. Constr., 12(3), 284-299.

29.

Smith, S.T. and Teng, J.G. (2001), "Interfacial stresses in plated beams", Eng. Struct., 23, 857-871.

30.

Spadea, G., Bencardino, F. and Swamy, R.N. (1998), "Structural behaviour of composite RC beams with externally bonded CFRP", J. Compos. Constr., 2(3), 132-137.

31.

Taljsten, B. (1996), "Strengthening of concrete prisms using the plate-bonding technique", Int. J. Fract., 82, 253-266.

32.

Taljsten, B. (1997), ''Strengthening of beams by plate bonding'', J. Mater. Civil Eng., 9(4), 206-212.

33.

Teng, J.G., Chen, J.F., Smith, S.T. and Lam, L. (2002), FRP-Strengthened RC Structures, John Wiley & Sons, New York.

34.

Teng, J.G., Smith, S.T., Yao, J. and Chen, J.F. (2003), "Intermediate crack-induced debonding in RC beams and slabs", Constr. Build. Mater., 17, 447-462.

35.

Tumialan, G., Serra, P., Nanni, A. and Belarbi, A. (1999), "Concrete cover delamination in reinforced concrete beams strengthened with carbon fiber reinforced polymer sheets", Proceedings of the Fourth International Symposium on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures (FRPRCS-4), Baltimore, November.

36.

Wang, W.W., Dai, J.G. and Harries, K.A. (2013), "Intermediate crack-induced debonding in RC beams strengthened with prestressed FRP laminates", J. Reinf. Plast. Comp., 32(23), 1842-1857.

37.

Wantanasiri, P. and Lenwari, A. (2011), "Debonding analysis for RC beams strengthened with FRP plates by energy release concepts", Proceedings of the 16th National Convention on Civil Engineering, Chonburi, Thailand, May. (in Thai)

38.

Wu, Z., Yuan, H., and Niu, H. (2002), "Stress transfer and fracture propagation in different kinds of adhesive joints", J. Eng. Mech., 128(5), 562-573.

39.

Wu, Z. and Niu, H. (2007), "Prediction of crack-induced debonding failure in R/C structures flexurally strengthened with externally bonded FRP composites", JSCE J. Mater. Concrete Struct. Pave., 63(4), 620-639.