Finite Element Modeling of Insulated FRP-Strengthened RC Beams Exposed to Fire
Publication: Journal of Composites for Construction
Volume 19, Issue 2
Abstract
The fire performance of reinforced concrete (RC) members strengthened with externally bonded fiber-reinforced polymer (FRP) laminates has been an issue of significant concern, particularly for building applications. To achieve structural fire-resistance ratings as specified in building design codes, an insulation layer often needs to be provided. This paper presents the first three-dimensional finite element (FE) approach for the fire performance simulation of insulated FRP-strengthened RC beams. The proposed approach gives careful considerations to the constitutive modeling of concrete, steel, and FRP, as well as the bond-slip behavior of FRP-to-concrete and steel-to-concrete interfaces. Comparisons between FE predictions and existing test data are presented to demonstrate the accuracy of the proposed FE approach. Numerical results obtained with the present FE approach show that the assumption of perfect bonding between FRP and concrete as adopted in previous numerical approaches leads to underestimations of deflections and thus unsafe predictions of fire resistance. The FE approach presented in the paper can be directly applied in performance-based fire safety design, or in parametric studies aimed at developing simplified design rules.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors are grateful for the financial support received from the National Basic Research Program of China (i.e., the 973 Program; Project No. 2012CB026201) and the Construction Industry Institute (Hong Kong)/PolyU Innovation Fund (Project No. 5-ZJE8). They are also grateful for a Postdoctoral fellowship awarded to the second author by Hong Kong Polytechnic University.
References
ABAQUS version 6.8 (2008). ABAQUS standard user’s manual, Vol. 1–3, Hibbitt, Karlsson & Sorensen, Pawtucket.
ACI. (1999). “Building code requirements for structural concrete (318-95) and commentary (318R-95).”, Farmington Hills, MI.
ACI. (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.”, Farmington Hills, MI.
Adelzadeh, M., Benichou, N., and Green, M. F. (2012). “Behaviour of fibre reinforced polymer-strengthened T-beams and slabs in fire.” Proc., ICE Struct. Build., 165(7), 361–371.
Ahmed, A., and Kodur, V. K. R. (2011a). “The experimental behavior of FRP-strengthened RC beams subjected to design fire exposure.” Eng. Struct., 33(7), 2201–2211.
Ahmed, A., and Kodur, V. K. R. (2011b). “Effect of bond degradation on fire resistance of FRP-strengthened reinforced concrete beams.” Composites Part B, 42(2), 226–237.
ASCE. (1992). “Structural fire protection.” Manuals and Rep. on Engineering Practice No. 78, ASCE Committee on Fire Protection, Structural Div., New York.
Barnes, R., and Fidell, J. (2006). “Performance in fire of small-scale CFRP strengthened concrete beams.” J. Compos. Constr., 503–508.
Bazant, Z. P., and Oh, B. H. (1983). “Crack band theory for fracture of concrete.” Mater. Struct., 16(3), 155–177.
Bisby, L. A. (2003). “Fire behavior of fiber-reinforced polymer (FRP) reinforced or confined concrete.” Ph.D. thesis, Queen’s Univ., Kingston, ON, Canada.
Bisby, L. A., Green, M. F., and Kodur, V. K. R. (2005). “Modeling the behavior of fiber reinforced polymer-confined concrete columns exposed to fire.” J. Compos. Constr., 15–24.
Blontrock, H. (2003). “Analysis and modeling of the fire resistance of concrete elements with externally bonded FRP reinforcement.” Ph.D. thesis, Ghent Univ., Ghent, Belgium.
Blontrock, H., Taerwe, L., and Vandevelde, P. (2000). “Fire tests on concrete beams strengthened with fiber composite laminates.” Proc., 3rd Ph.D. Symp. in Civil Engineering, Institute of Structural Engineering, Univ. of Agricultural Sciences, Vienna, Austria, 151–161.
Cao, S. H., Wang, X., and Wu, Z. S. (2011). “Evaluation and prediction of temperature-dependent tensile strength of unidirectional carbon fiber-reinforced polymer composites.” J. Reinf. Plast. Compos., 30(9), 799–807.
Cao, S. H., Wu, Z. S., and Wang, X. (2009). “Tensile properties of CFRP and hybrid FRP composites at elevated temperatures.” J. Compos. Mater., 43(4), 315–330.
Chen, G. M., Chen, J. F., and Teng, J. G. (2012). “Behaviour of FRP-to-concrete interfaces between two adjacent cracks: A numerical investigation on the effect of bondline damage.” Constr. Build. Mater., 28(1), 584–591.
Chen, G. M., Teng, J. G., and Chen, J. F. (2011). “Finite-element modeling of intermediate crack debonding in FRP-plated RC beams.” J. Compos. Constr., 339–353.
Chowdhury, E. U., Bisby, L. A., Green, M. F., Benichou, N., and Kodur, V. K. R. (2012). “Heat transfer and structural response modelling of FRP confined rectangular concrete columns in fire.” Constr. Build. Mater., 32, 77–89.
Chowdhury, E. U., Eedson, R., Bisby, L. A., Green, M. F., Benichou, N., and Kodur, V. K. R. (2008). “Mechanical characterization of fibre reinforced polymers for numerical fire endurance modelling.” Proc., 5th Int. Conf. Structures in Fire, Research Publishing Services, Singapore, 499–507.
Chowdhury, E. U., Eedson, R., Green, M. F., Bisby, L. A., and Benichou, N. (2011). “Mechanical characterization of fiber reinforced polymers materials at high temperature.” Fire Technol., 47(4), 1063–1080.
Comite Euro-International du Beton—Federation International de la Precontrainte (CEB-FIP). (1993). CEB-FIP Model Code 90, Thomas Telford, London.
Dai, J. G., Gao, W. Y., and Teng, J. G. (2013). “Bond-slip model for FRP laminates externally bonded to concrete at elevated temperature.” J. Compos. Constr., 217–228.
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., 52–62.
Dai, J. G., Ueda, T., and Sato, Y. (2006). “Unified analytical approaches for determining shear bond characteristics of FRP-concrete interfaces through pullout tests.” J. Adv. Concr. Technol., 4(1), 133–145.
Deuring, M. (1994). “Fire tests on strengthened reinforced concrete beams.”, Swiss Federal Laboratories for Materials Testing and Research, Dubendorf, Switzerland.
Ellobody, E. A. M., and Bailey, C. G. (2009). “Modelling of unbonded post-tensioned concrete slabs under fire conditions.” Fire Saf. J., 44(2), 159–167.
EN 1991-1-2. (2002). “Eurocode 1: Actions on structures. Part 1–2: General actions-actions on structures exposed to fire.” British Standards Institution, London.
EN 1992-1-2. (2004). “Eurocode 2: Design of concrete structures. Part 1–2: General rules-structural fire design.” British Standards Institution, London.
Federation International du Beton (FIB). (2001). “Externally bonded FRP reinforcement for RC structures.” fib Bulletin 14, fib Task Group 9.3, fib, Lausanne, Switzerland.
Federation International du Beton (FIB). (2007). “Fire design of concrete structures—Materials, structures and modeling.” fib Bulletin 38, Working Party 4.3-1, fib, Lausanne, Switzerland.
Gao, W. Y. (2013). “Fire resistance of FRP-strengthened RC beams: Numerical simulation and performance-based design.” Ph.D. thesis, Hong Kong Polytechnic Univ., Hong Kong, China.
Gao, W. Y., Dai, J. G., and Teng, J. G. (2013). “Finite element modeling of reinforced concrete beams exposed to fire.” Eng. Struct., 52, 488–501.
Gao, W. Y., Dai, J. G., and Teng, J. G. (2014). “Simple method for predicting temperatures in reinforced concrete beams exposed to a standard fire.” Adv. Struct. Eng., 17(4), 573–590.
Gao, W. Y., Hu, K. X., and Lu, Z. D. (2010). “Fie resistance experiments of insulated CFRP strengthened reinforced concrete beams.” Chin. Civ. Eng. J., 43(3), 15–23.
Gao, W. Y., Teng, J. G., and Dai, J. G. (2012). “Effect of temperature variation on the full-range behavior of FRP-to-concrete bonded joints.” J. Compos. Constr., 671–683.
Green, M. F., Benichou, N., Kodur, V. K. R., and Bisby, L. A. (2007). “Design guidelines for fire resistance of FRP-strengthened concrete structures.” 8th Int. Conf. on FRP for Reinforced Concrete Structures (FRPRCS-8), Univ. of Patras, Patras, Greece.
Griffis, C. A., Masmura, R. A., and Chang, C. I. (1981). “Thermal response of graphite epoxy composite subjected to rapid heating.” J. Compos. Mater., 15(5), 427–442.
Han, L. H., Zheng, Y. Q., and Teng, J. G. (2006). “Fire resistance of RC and FRP-confined RC columns.” Mag. Concr. Res., 58(8), 533–546.
Hawileh, R. A., Naser, M., Zaidan, W., and Rasheed, H. A. (2009). “Modeling of insulated CFRP-strengthened reinforced concrete T-beam exposed to fire.” Eng. Struct., 31(12), 3072–3079.
Klamer, E. (2006). “The influence of temperature on concrete structures strengthened with externally bonded CFRP.” Research Rep., Eindhoven Univ. of Technology, Eindhoven, Netherlands.
Kodur, V. K. R., and Ahmed, A. (2010). “Numerical model for tracing the response of FRP-strengthened RC beams exposed to fire.” J. Compos. Constr., 730–742.
Kong, F. K., and Evans, R. H. (1987). Reinforced and prestressed concrete, 3rd Ed., Chapman & Hall, London.
Lee, J., and Fenves, G. (1998). “Plastic damage model for cyclic loading of concrete structures.” J. Eng. Mech., 892–900.
Leone, M., Matthys, S., and Aiello, M. A. (2009). “Effect of elevated service temperature on bond between FRP EBR systems and concrete.” Composites Part B, 40(1), 85–93.
Liu, F. T., Wu, B., and Wei, D. M. (2009). “Failure modes of reinforced concrete beams strengthened with carbon fiber sheet in fire.” Fire Saf. J., 44(7), 941–950.
Lu, X. Z., 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.
Lubliner, J., Oliver, J., Oller, S., and Onate, E. (1989). “A plastic-damage model for concrete.” Int. J. Solids Struct., 25(3), 299–326.
Mouritz, A. P., and Gibson, A. G. (2006). Fire properties of polymer composite materials, Springer, Dordrecht, Netherlands.
Rafi, M. M., Nadjai, A., and Ali, F. (2008). “Finite element modeling of carbon fiber-reinforced polymer reinforced concrete beams under elevated temperatures.” ACI Struct. J., 105(6), 701–710.
Reni, G., Abecassis Empis, C., and Carvel, R. (2007). The Dalmarnock fire tests: Experiments and modelling, School of Engineering and Electronics, Univ. Edinburgh, Edinburgh, U.K.
Sadaoui, A., and Khennane, A. (2012). “Effect of transient creep on behavior of reinforced concrete beams in a fire.” ACI Mater. J., 109(6), 607–615.
Stratford, T. J., Gillie, M., Chen, J. F., and Usmani, A. S. (2009). “Bonded fibre reinforced polymer strengthening in a real fire.” Adv. Struct. Eng., 12(6), 867–878.
Tan, K. H., and Zhou, Y. Q. (2011). “Performance of FRP-strengthened beams subjected to elevated temperatures.” J. Compos. Constr., 304–311.
Teng, J. G., and Chen, J. F. (2009). “Mechanics of debonding in FRP-plated RC beams.” ICE Proc. Struct. Build., 162(5), 335–345.
Teng, J. G., Chen, J. F., Smith, S. T., and Lam, L. (2002). FRP-strengthened RC structures, Wiley, London, U.K., 245.
Wang, K., Young, B., and Smith, S. T. (2011). “Mechanical properties of pultruded carbon fibre-reinforced polymer (CFRP) plates at elevated temperatures.” Eng. Struct., 33(7), 2154–2161.
Wang, Y. C., Wong, P. M. H., and Kodur, V. (2007). “An experimental study of the mechanical properties of fibre reinforced polymer (FRP) and steel reinforcing bars at elevated temperatures.” Compos. Struct., 80(1), 131–140.
Williams, B. (2004). “Fire performance of FRP-strengthened reinforced concrete flexural members.” Ph.D. thesis, Queen’s Univ., Kingston, ON, Canada.
Williams, B., Kodur, V. K. R., Green, M. F., and Bisby, L. A. (2008). “Fire endurance of fiber-reinforced polymer strengthened concrete T-beams.” ACI Struct. J., 105(1), 60–67.
Wu, B., and Lu, J. Z. (2009). “A numerical study of the behaviour of restrained RC beams at elevated temperatures.” Fire Saf. J., 44(4), 522–531.
Wu, B., and Wan, Z. J. (2009). “Experimental investigation into fire resistance of reinforced concrete beams strengthened in flexure with carbon fiber sheets.” J. South Chin. Univ. Technol., 40(6), 26–41.
Zhou, C. D. (2005). “Fire performance of GFRP reinforced concrete.” Research Rep., Dept. of Civil Engineering, Tongji Univ., Shanghai, China.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 19 • Issue 2 • April 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 23, 2014
Accepted: Jun 25, 2014
Published online: Aug 6, 2014
Discussion open until: Jan 6, 2015
Published in print: Apr 1, 2015
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.