Indirect Identification Method of Bilinear Interface Laws for FRP Bonded on a Concrete Substrate
Publication: Journal of Composites for Construction
Volume 16, Issue 2
Abstract
The mechanical response of Reinforced Concrete (RC) beams strengthened by an Externally Bonded Reinforcement (EBR) made out of Fiber-Reinforced Polymers (FRPs) is deeply influenced by the interaction between the concrete substrate and the FRP system, either cured-in-place (sheets) or preformed (plates). In particular, the strength of FRP-EBR RC beams is often controlled by debonding phenomena to develop at the adhesive-to-concrete interface. The most recent theoretical formulations and some experimental results obtained in the last years pointed out the differences that characterize the debonding strength of FRP sheets and plates. According to the findings of those studies, the fracture energy is a fundamental parameter governing the debonding phenomenon. However, determining its value is not sufficient for simulating the behavior of the FRP-to-concrete interface and modeling relevant problems such as intermediate debonding in RC beams externally strengthened by FRP. Consequently, formulating and calibrating local bond-slip models, which take into account the different behavior of sheets and plates, is of fundamental importance for modeling FRP-strengthened RC members. This paper is aimed at identifying bond-laws for sheets and plates through an Indirect Identification Method (IndIM), recently implemented and validated by the authors. A wide collection of experimental results obtained by pull-out tests on FRP sheets and plates is first reported and then employed for identifying the previously noted bond-slip laws. Finally, the results of the identification procedure demonstrate that the debonding phenomenon, described as a fracture process in mode II, should be modeled by assuming different bond-slip relationships for FRP plates and sheets.
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Acknowledgments
The present paper was developed within the Research Project “DPC-Reluis project 2010-2013.”
References
Aiello, M. A., and Leone, M. (2005). “Experimental bond analysis of concrete—FRP (fiber reinforced polymer) reinforced.” Proc. FIB Symp. Keep Concrete Attractive, Balasz and Borosnyoi, eds., Budapest, Hungary.
Bilotta, A., Di Ludovico, M., and Nigro, E. (2009a). “Influence of effective bond length on FRP-concrete debonding under monotonic and cyclic actions.” Proc. 9th Int. Symp. on Fiber Reinforced Polymer Reinforcement for Concrete Structures, Oehlers, Griffith, and Seracino, eds., Adelaide, Australia.
Bilotta, A., Di Ludovico, M., and Nigro, E. (2009b). “FRP debonding on concrete members. Part I: experimental investigation.” Proc. 9th Int. Symp. on Fiber Reinforced Polymer Reinforcement for Concrete Structures, Oehlers, Griffith, and Seracino, eds., Adelaide, Australia.
Bilotta, A., Di Ludovico, M., and Nigro, E. (2009c). “FRP debonding on concrete members. Part II: Capacity model calibration.” Proc. 9th Int. Symp. on Fiber Reinforced Polymer Reinforcement for Concrete Structures, Oehlers, Griffith, and Seracino, eds., Adelaide, Australia.
Bilotta, A., Ceroni, F., Nigro, E., Di Ludovico, M., Pecce, M. R., and Manfredi, G. (2011). “Bond efficiency of EBR and NSM FRP systems for strengthening of concrete members.” J. Compos. Construc.JCCOF2, in press.
Brosens, K., and van Gemert, D (1997). “Anchoring stresses between concrete and carbon fiber reinforced laminates.” Proc. 3rd Int. Symp. on Non-metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Tokyo, Japan, 271–278.
Brosens, K. (2001). “Anchorage of externally bonded steel plates and CFRP laminates for the strengthening of concrete elements.” Ph.D. thesis, K.U. Leuven.
Ceroni, F., and Pecce, M. (2010). “Evaluation of bond strength and anchorage systems in concrete elements strengthened with CFRP sheets.” J. Compos. Construc.JCCOF2, 14(5), 521–530.
Chajes, M. J., Finch, W. W., Januszka, T. F., and Thomson, T. A. (1996). “Bond and force transfer of composite-material plates adhered to concrete.” ACI Struct. J.ASTJEG, 93(2), 208–217,
Chen, J. F., and Teng, J. G. (2001). “Anchorage strength models for FRP and plates bonded to concrete.” J. Struct. Div., Am. Soc. Civ. Eng., 127(7), 784–791.
CNR—National Council for Research. (2004). “Guide for the design and construction of externally bonded FRP systems for strengthening existing structures—Materials, RC and PC structures, masonry structures.” 〈http://www.cnr.it/documenti/norme/IstruzioniCNR_DT203_2006_eng.pdf〉.
Dai, J. G., and Ueda, T. (2003). “Local bond stress slip relations for FRP sheets concrete interfaces.” Proc. 6th Int. Symp. on FRP Reinforcement for Concrete Structures, World Scientific Publications, Singapore, 143–152.
Dai, J., Ueda, T., and Sato, Y. (2005). “Development of nonlinear bond stress-slip model of FRP sheet-concrete interfaces with a simple method.” J. Compos. Constr., 9(1), 52–62.
De Lorenzis, L, Miller, B., and Nanni, A. (2001). “Bond of fiber-reinforced polymer laminates to concrete.” ACI Mater. J.AMAJEF, 98(3), 256–264.
European Committee for Standardization. (2002). EN 1990—Eurocode—Basic of Structural Design, Brussels, Belgium.
Faella, C., Martinelli, E., Nigro, E, Sabatino, M., Salerno, N., and Mantegazza, G. (2002a). “Aderenza tra calcestruzzo e Lamine di FRP utilizzate come placcaggio di elementi inflessi. Parte I: Risultati sperimentali.” Proc. XIV C.T.E. Conf., C.T.E., Milan, Italy, 237–245 (in Italian).
Faella, C., Martinelli, E., and Nigro, E. (2002b). “Aderenza tra calcestruzzo e Lamine di FRP utilizzate come placcaggio di elementi inflessi Parte II: modelli teorici ed elaborazioni numeriche,” Proc. XIV C.T.E. Conf., C.T.E., Milan, Italy, 237–245 (in Italian).
Faella, C., Martinelli, E., and Nigro, E. (2003). “Interface behaviour in FRP plates bonded to concrete: Experimental tests and theoretical analyses.” Proc. Int. Conf. on Advanced Materials for Construction of Bridges, Buildings and other Structures - III, Berkeley Electronic Press, Berkeley, CA, 〈http://services.bepress.com/eci/advanced_materials/3/〉 (Dec. 15, 2010).
Faella, C., Martinelli, E., and Nigro, E. (2008). “Formulation and validation of a theoretical model for intermediate debonding in FRP strengthened RC beams.” Composites Part B, 39(4), 645–655.
Faella, C., Martinelli, E., and Nigro, E. (2009). “Direct versus indirect method for identifying FRP-to-concrete interface relationships.” J. Compos. Constr.JCCOF2, 13(3), 226–233.
Ferracuti, B., Martinelli, E., Nigro, E., and Savoia, M. (2007a). “Fracture energy and design rules against FRP-concrete debonding.” Proc. the 8th FRPRCS Conf., ed., Patras, Greece.
Ferracuti, B., Savoia, M., and Mazzotti, C. (2007b). “Interface law for FRP-concrete delamination composite structures.” Compos. Struct., 80, 523–531.
fib Bulletin No. 14. (2001). “Externally bonded FRP reinforcement for RC structures.” Technical report prepared by the Working Party EBR of Task Group 9.3, International Federation for Structural Concrete, Lausanne, Switzerland.
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.ENSTDF, 27(6), 920–937.
Maeda, T., Asano, Y., Sato, Y., Ueda, T., and Kakuta, Y. (1997). “A study on bond mechanism of carbon fiber sheet.” Proc. 3rd Int. Symp. on Non-metallic (FRP) Reinforcement for Concrete Structures, Japan Concrete Institute, Tokyo, Japan, 279–285.
Mazzotti, C., Savoia, M., Ferracuti, B. (2009). “A new single-shear set-up for stable debonding of FRP-concrete joints.” Constr. Build. Mater.CBUMEZ, 23(4), 1529–1537.
McSweeney, B. M., and Lopez, M. M. (2005). “FRP-concrete bond behavior: A parametric study through pull-off testing.” Proc. 7th Int. Symp. on FRP Reinforcement for Concrete Structures, ACI, Farmington Hills, MI, 441–460.
Monti, G., Alessandri, S., and Santini, S. (2009). “Design by testing: A procedure for the statistical determination of capacity models.” J. Constr. Build Mater., 23(4), 1487–1494.
Nakaba, K., Kanakubo, T., Furuta, T., and Yoshizawa, H. (2001). “Bond behavior between fiber-reinforced polymer laminates and concrete.” ACI Struct. J.ASTJEG, 98(3), 359–367.
Nigro, E., Martinelli, E., Di Ludovico, M., and Bilotta, A. (2008a). “Concrete interface relationships under monotonic and cyclic actions.” Proc. 4th Int. Conf. on FRP Composites in Civil Engineering (CICE2008), Masoud Motavalli, Zurich, Switzerland.
Nigro, E., Di Ludovico, M., and Bilotta, A. (2008b). “FRP-concrete debonding: Experimental tests under cyclic actions.” Proc., 14th World Conf. on Earthquake Engineering, IAEE Publisher, Tokyo, Japan.
Nigro, E., Di Ludovico, M., Bilotta, A. (2011). “Experimental investigation on FRP-concrete debonding under cyclic actions.” J. Mater. Civ. Eng.JMCEE7, 23(4), 360–371.
Oehlers, D. J., and Moran, J. P. (1990). “Premature failure of externally plated reinforced-concrete beams.” J. Struct. Eng., 116(4), 978–995.
Savoia, M., et al. (2009). “Experimental round robin test on FRP concrete bonding.” Proc. FRPRCS9, Oehlers, Griffith, and Seracino, eds., Adelaide, Australia
Seracino, R., Saifulnaz, M. R.R., and Oehlers, D. J. (2007). “Generic debonding resistance of EB and NSM plate-to-concrete joints.” J. Compos. Constr.JCCOF2, 11(1), 62–70.
Takeo, K., Matsushita, H., Makizumix, T., and Nagashima, G. (1997). “Bond characteristics of CFRP sheets in the CFRP bonding technique.” Proc. of Japan Concrete Institute, Japan Concrete Institute, Tokyo, Japan, 19(2), 1599–1604.
Teng, J. G., Chen, J. F., Smith, S. T., and Lam, L. (2002). FRP: Strengthened RC structures. Wiley, Chichester, U.K.
Tounsi, A., Hassaine Daouadji, T., Benyoucef, S., and Addabedia, E. A. (2009). “Interfacial stresses in FRP-plated RC beams: Effect of adherend shear deformations.” Int. J. Adhes. Adhes.IJAADK, 29(4), 343–351.
Travassos, N., Ripper, T., and Appleton, J. (2005). “Bond stresses characterization on CFRP-RC interfaces.” Proc. 3rd Int. Conf. Composites in Construction, Hamelin, P., Bigaud, D., Ferrier, E., and Jacquelin, E., eds., Lyon, France.
Ueda, T., Dai, J. G., and Sato, Y. (2003). “A nonlinear bond stress-slip relationship for FRP sheet-concrete interface.” Proc. Int. Symp. on Latest Achievement of Technology and Research on Retrofitting Concrete Structures, Japan Concrete Institute, Tokyo, Japan 113–120.
Ueda, T., and Dai, J. (2005). “Mode II fracture energy of FRP-concrete interface: Its evaluation and roles in interface modeling and anchorage design.” Proc. 11th Int. Conf. on Fracture, Turin, Italy, 〈http://www.icf11.com/proceeding/EXTENDED/4303.pdf〉.
Ueda, T., Sato, Y., and Asano, Y. (1999). “Experimental study on bond strength of continuous carbon fiber sheet.” Proc. 4th Int. Symp. on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structure, ACI, Farmington Hills, MI, 407–416.
Wu, Z. S., Yuan, H., Yoshizawa, H., and Kanakubo, T. (2001). Experimental/analytical study on interfacial fracture energy and fracture propagation along FRP-concrete interface, ACI International SP-201-8, 133–152.
Yao, J., Teng, J. G., and Chen, J. F. (2005). “Experimental study on FRP-to-concrete bonded joints.” Comp., Part BCPBEFF, 36(2), 99–113.
Yuan, H., Teng, J. G., Seracino, R., Wu, Z. S., and Yao, J. (2004). “Full-range behaviour of FRP-to-concrete bonded joints.” Eng. Struct.ENSTDF, 26(5), 553–565.
Zhao, H. D., Zhang, Y., and Zhao, M. (2000). “Research on the bond performance between CFRP plate and concrete.” Proc. 1st Conf. on FRP Concrete Structures of China, 247–253.
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Published In
Journal of Composites for Construction
Volume 16 • Issue 2 • April 2012
Pages: 171 - 184
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Mar 6, 2011
Accepted: Aug 30, 2011
Published online: Aug 30, 2011
Published in print: Apr 1, 2012
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