Flexural Strengthening of RC Beams with Externally Bonded CFRP Systems: Test Results and 3D Nonlinear FE Analysis
Publication: Journal of Composites for Construction
Volume 12, Issue 2
Abstract
This paper presents experimental results and a numerical analysis of the reinforced concrete (RC) beams strengthened in flexure with various externally bonded carbon fiber-reinforced polymer (CFRP) configurations. The aim of the experimental work was to investigate the parameters that may delay the intermediate crack debonding of the bottom CFRP laminate, and increase the load carrying capacity and CFRP strength utilization ratio. Ten rectangular RC specimens with a clear span of , categorized in two series, were tested to evaluate the effect of using the additional U-shaped CFRP systems on the intermediate crack debonding of the bottom laminate. Two different configurations of the additional systems were proposed, namely, continuous U-shaped wet layup sheets and spaced side-bonded CFRP L-shaped laminates. The fiber orientation effect of the side-bonded sheets was also investigated. A numerical analysis using an incremental nonlinear displacement-controlled 3D finite-element (FE) model was developed to investigate the flexural and CFRP/concrete interfacial responses of the tested beams. The finite-element model accounts for the orthotropic behavior of the CFRP laminates. An appropriate bond-slip model was adopted to characterize the behavior of the CFRP/concrete interface. Comparisons between the FE predictions and experimental results show very good agreement in terms of the load-deflection and load-strain relationships, ultimate capacities, and failure modes of the beams.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The experimental research was carried out at the Structural Laboratory of Concrete Structures, University of Lodz, Poland. Financial support was provided by the Polish State Committee for Scientific Research in two research grants: No. UNSPECIFIED7 T07E 030 16 of the Polish Research Scientific Committee and No. UNSPECIFIED8 T07E 006 21 of the Ministry of Scientific Research and Information Technology, whose support is gratefully acknowledged. This research was also funded in part by the Natural Sciences and Engineering Research Council of Canada (NSERCNSERC) and the Canadian Network of Centres of Excellence on Intelligent Sensing for Innovative Structures (ISIS Canada). KWN is Canada Research Chair in Advanced Engineered Material Systems and the support of this program is gratefully acknowledged.
References
Abdel Baky, H. M., Ebead, U. A., Masmoudi, R., and Neale, K. W. (2004). “Analysis of the flexural response of FRP-strengthened concrete beams.” Advanced composite materials in bridges and structures, M. El-Badry and L. Dunaszegi, eds., Canadian Society for Civil Engineering.
ADINA. (2004a). Automatic dynamic incremental nonlinear analysis: Finite element software version 8.2, ADINA R & D, Inc., Watertown, Mass.
ADINA. (2004b). Theory and modeling guide: Volume I, Chapter 3, version 8.2, ADINA R & D, Inc., Watertown, Mass.
American Concrete Institute (ACI). (2002). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI No. 440.2R-02, Farmington Hills, Mich.
Brena, S. F., Bramblett, R. M., Wood, S. L., and Kreger, M. E. (2003). “Increasing flexural capacity of reinforced concrete beams using carbon fibre-reinforced polymer composites.” ACI Struct. J., 100(1), 36–46.
Brena, S. F., and Macri, M. M. (2004). “Effect of carbon fibre reinforced polymer laminate configuration on the behaviour of strengthened reinforced concrete beams.” J. Compos. Constr., 8(3), 229–240.
Chicoine, T. (1997). “Conception et analyse d’ancrages sur les poutres renforcées en flexion à l’aide de matériaux composites.” Mémoire de maîtrise, Département de génie civil, Université de Sherbrooke, Canada.
Ebead, U. A., and Marzouk, H. (2005). “Tension-stiffening model for FRP-strengthened RC concrete two-way slabs.” Mater. Struct., 38, 193–200.
Ebead, U. A., and Neale, K. W. (2007). “Mechanics of fibre-reinforced polymer—Concrete interfaces.” Can. J. Civ. Eng., 34, 367–377.
Ebead, U. A., Neale, K. W., and Bizindavyi, L. (2004). “On the interfacial mechanics of FRP-strengthened concrete structures.” FRP composites in civil engineering—CICE 2004, R. Seracino, ed., Balkema Publications, Rotterdam, The Netherlands, 351–359.
Ehsani, M. R., and Saadatmanesh, H. (1990). “Fibre composite plates for strengthening bridge beams.” Compos. Struct., 15, 343–355.
FIB. (2001). “Externally bonded FRP reinforcement for RC structures.” Technical Rep., Int. Federation for Structural Concrete (fib), Bulletin No. 14, Lausanne, Switzerland.
Kaminska, M. E., and Kotynia, R. (2000). “Experimental research on RC beams strengthened with CFRP strips.” Rep. No. 9, Dept. of Concrete Structures, Technical Univ. of Lodz, Poland.
Kishi, N., Zhang, G., and Mikami, H. (2005). “Numerical cracking and debonding analysis of RC beams reinforced with FRP sheet.” J. Compos. Constr., 9(6), 507–514.
Kotynia, R. (1999). “Ductility and load capacity of reinforced concrete members strengthened with CFRP laminates.” Ph.D. thesis, Technical Univ. of Lodz, Poland.
Kotynia, R. (2000). “Load bearing capacity and strains of reinforced concrete beams strengthened with carbon composite plates.” Proc. 3rd Int. PhD Symp. in Civil Engineering, Vol. 2, Vienna, Austria, 193–202.
Kotynia, R. (2005). “Debonding failures of RC beams strengthened with externally bonded strips.” Bond behaviour of FRP in structures, J. F. Chen and J. G. Teng, eds., Int. Institute for FRP in Construction, Hong Kong, 255–260.
Kotynia, R., and Kaminska, M. E. (2003). “Ductility and failure mode of RC beams strengthened for flexure with CFRP.” Rep. No. 13, Dept. of Concrete Structures, Technical Univ. of Lodz, Poland.
Lu, X. Z., Ye, L. P., Teng, J. G., Ye, L. P., and Jiang, J. J. (2005). “Bond–slip models for FRP sheets/plates bonded to concrete.” Eng. Struct., 27(6), 920–937.
Neale, K. W., Ebead, U. A., Abdel Baky, H. M., Elsayed, W. E., and Godat, A. (2005). “Modelling of debonding phenomena in FRP-strengthened concrete beams and slabs.” Bond behaviour of FRP in structures, J. F. Chen and J. G. Teng, eds., Int. Institute for FRP in Construction, Hong Kong, 45–54.
Neubauer, U., and Rostásy, F. S. (2001). “Debonding mechanism and model for CFRP-plates as external reinforcement for concrete members.” Proc., Composites in Construction—CCC2001, Balkema, Porto, Portugal, Vol. 1, 467–472.
Nitereka, C., and Neale, K. W. (1999). “Analysis of reinforced concrete beams strengthened in flexure with composite laminates.” Can. J. Civ. Eng., 26, 646–654.
Niu, H., and Wu, Z. (2006). “Effects of FRP-concrete interface bond properties on the performance of RC beams strengthened in flexure with externally bonded FRP sheets.” J. Mater. Civ. Eng., 18(5), 723–731.
Oehlers, D. J. (1992). “Reinforced concrete beams with plates glued to their soffits.” J. Struct. Eng., 118(8), 2023–2038.
Rabinovitch, O., and Frostig, Y. (2001). “Delamination failure of RC beams strengthened with FRP strips—A closed-form high-order and fracture mechanics approach.” J. Eng. Mech., 127(8), 852–861.
Ritchie, P. A., Thomas, D., Lu, L.-W., and Connelly, G. (1991). “External reinforcement of concrete beams using fibre reinforced plastics.” ACI Struct. J., 88(4), 490–500.
Sand, B., and Remlo, H. (2001). “RC beams with externally bonded CFRP: Finite element modelling of delamination failure.” Doc. No. NTAS F2001-32, Interreg Nordkaotten Institute.
Smith, S. T., and Teng, J. G. (2002a). “FRP-strengthened RC beams. I: Review of debonding strength models.” Eng. Struct., 24(4), 385–395.
Smith, S. T., and Teng, J. G. (2002b). “FRP-strengthened RC structures. II: Assessment of debonding strength models.” Eng. Struct., 24(4), 397–417.
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.
Takahashi, Y., Sato, Y., Ueda, T., Maeda, T., and Kobayashi, A. (1997). “Flexural behaviour of RC beams with externally bonded carbon fibre sheet.” Proc., Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, 327–334.
Teng, J. G., Lu, X. Z., Ye, L. P., and Jiang, J. J. (2004). “Recent research on intermediate crack-induced debonding in FRP-strengthened RC beams.” Advanced composite materials in bridges and structures, M. El-Badry and L. Dunaszegi, eds., Canadian Society for Civil Engineering.
Wong, R. S. Y., and Vecchio, F. J. (2003). “Toward modeling of reinforced concrete members with externally bonded fibre-reinforced polymer composites.” ACI Struct. J., 100(1), 47–55.
Yang, H., Wu, Z. S., and Yoshizawa, H. (2001). “Theoretical solutions on interfacial stress transfer of externally bonded steel/composite laminates.” J. Structural Mechanics and Earthquake Engineering, JSCE, 18(1), 27–39.
Yang, Z., Chen, J., and Proverbs, D. (2003). “Finite element modelling of concrete cover separation failure in FRP plated RC beams.” Constr. Build. Mater., 17(1) 3–13.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 12 • Issue 2 • April 2008
Pages: 190 - 201
Copyright
© 2008 ASCE.
History
Received: Oct 24, 2006
Accepted: Feb 27, 2007
Published online: Apr 1, 2008
Published in print: Apr 2008
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.