Effect of Longitudinal Steel Ratio on Behavior of RC Beams Strengthened with FRP Composites: Experimental and FE Study
Publication: Journal of Composites for Construction
Volume 19, Issue 1
Abstract
This study experimentally and numerically investigates the effect of longitudinal steel ratio on the flexural performance of RC beams externally strengthened with fiber-reinforced polymer (FRP) composites. The experimental program consisted of testing 11 beams under four-point bending until failure. Each beam was duplicated to verify the repeatability of the results. Three beams were tested as control specimens; the remaining eight beams were externally strengthened in flexure with FRP composites. The primary experimentally studied parameters were longitudinal steel ratio and axial FRP stiffness. Three different steel ratios were examined. For the lowest steel ratio, four different FRP systems with six axial stiffness values were investigated. However, for the other two steel ratios, only one FRP system was studied. In addition to the experimental program, a numerical study utilizing nonlinear finite-element (FE) analysis was conducted. As a result of the numerical study, new FRP stiffness and reinforcement parameters were introduced in this research. These parameters were used in the categorization of failure modes of FRP-upgraded beams.
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Acknowledgments
The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for its funding of this research through the research group project No. RGP-VPP-310. Thanks are also extended to the MMB Chair for Research and Studies in Strengthening and Rehabilitation of Structures, at the Department of Civil Engineering, King Saud University for providing technical support.
References
American Concrete Institute (ACI). (2002). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.”, American Concrete Institute, Detroit, MI.
American Concrete Institute (ACI). (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.”, American Concrete Institute, Detroit, MI.
American Concrete Institute (ACI). (2011). “Building code requirements for structural concrete and commentary.”, American Concrete Institute, Detroit, MI.
ASTM. (2009). “Standard test methods for tension testing of metallic materials.” ASTM E8/E8M, American Society for Testing and Materials, West Conshohocken, PA.
ASTM. (2010). “Standard test method for compressive strength of cylindrical concrete specimens.” ASTM C39/C39M, American Society for Testing and Materials, West Conshohocken, PA.
Bizindavyi, L., and Neale, K. W. (1999). “Transfer lengths and bond strengths for composites bonded to concrete.” J Compos. Constr, 153–160.
Ceroni, F. (2010). “Experimental performances of RC beams strengthened with FRP materials.” Constr. Build Mater., 24(9), 1547–1559.
Chang, F. K., and Chang, K. Y. (1987). “A progressive damage model for laminated composites containing stress concentration.” J. Compos. Mater., 21(9), 834–855.
Chen, J. F., and Teng, J. G. (2001). “Anchorage strength models for FRP and steel plates bonded to concrete.” J. Struct. Eng., 784–791.
El-Hacha, R., Green, M., and Wight, G. (2010). “Effect of severe environmental exposures on CFRP wrapped concrete columns.” J. Compos. Constr, 83–93.
Elsanadedy, H. M., Almusallam, T. H., Alsayed, S. H., and Al-Salloum, Y. A. (2013). “Flexural strengthening of RC beams using textile reinforced mortar—Experimental and numerical study.” Compos Struct., 97, 40–55.
Esfahani, M., Kianoush, M., and Tajari, A. (2007). “Flexural behaviour of reinforced concrete beams strengthened by CFRP sheets.” Eng. Struc., 29(10), 2428–2444.
Fédération internationale du béton (fib). (2001). “Externally bonded FRP reinforcement for RC structures.”, Swiss Federal Institute of Technology, Lausanne, Switzerland, 138.
Grande, A., Imbimbo, M., and Rasulo, A. (2009). “Effect of transverse steel on the response of RC beams strengthened in shear by FRP: Experimental study.” J. Compos. Constr., 405–414.
Intelligent Sensing for Innovative Structures (ISIS) Canada. (2001). “Strengthening reinforced concrete structures with externally-bonded fiber reinforced polymers.” ISIS Canada Design Manual, No. 4, Winnipeg, Canada.
LS-DYNA [Computer software]. Livermore, CA, Livermore Software Technology Corporation.
Lu, X. Z., Teng, J. G., Ye, L. P., and Jiang, J. J. (2005). “Bond-slip models for sheets/plates bonded to concrete.” Eng. Struct., 27(6), 920–937.
Mahjoub, R., and Hashemi, S. H. (2010). “Finite element analysis of RC beams strengthened with FRP sheets under bending.” Aust. J. Basic Appl. Sci., 4(5), 773–778.
Murray, Y. D. (2007). “Users manual for LS-DYNA concrete material model 159.”, Federal Highway Administration, Washington, DC.
Murray, Y. D., Abu-Odeh, A., and Bligh, R. (2007). “Evaluation of concrete material model 159.”, Federal Highway Administration, Washington, DC.
Neagoe, C. A. (2011). “Concrete beams reinforced with CFRP laminates.” MS thesis, Polytechnic University of Catalonia, Spain.
Norris, T., Saadatmanesh, H., and Ehsani, M. R. (1997). “Shear and flexural strengthening of RC beams with carbon fiber sheets.” J. Struct. Eng., 903–911.
Papanicolaou, C. G., Triantafillou, T. C., Bournas, D. A., and Lontou, P. V. (2006). “TRM as strengthening and seismic retrofitting material of concrete structures.” Proc., ICTRC’2006—First Int. RILEM Conf. on Textile Reinforced Concrete (ICTRC), RILEM Publications SARL, Bagneux, France, 331–340.
Pham, H., and Al-Mahaidi, R. (2004). “Assessment of available predictions models for the strength of FRP retrofitted RC beams.” Compos. Struct., 66(1–4), 601–610.
Saadatmanesh, H., and Malek, A. M. (1998). “Design guidelines for flexural strengthening of RC beams with FRP plates.” J. Compos. Constr, 158–164.
Siddiqui, N. A. (2009). “Experimental investigation of RC beams strengthened with externally bonded FRP composites.” Latin Am. J. Solids Struct., 6, 343–362.
Smith, S. T., and Teng, J. G. (2002). “FRP-strengthened RC beams. I: Review of debonding strength models.” Eng. Struct., 24(4), 385–395.
Sobuz, H., Ahmed, E., Hasan, N., and Uddin, M. (2011). “Use of carbon fiber laminates for strengthening reinforced concrete beams in bending.” Int. J. Civ. Struct. Eng., 2(1), 67–84.
Soudki, K., El-Salakawy, E., and Craig, B. (2007). “Behavior of CFRP strengthened reinforced concrete beams in corrosive environment.” J. Compos. Constr., 291–298.
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(6–7), 447–462.
Zhang, A., Jin, W., and Li, G. (2006). “Behavior of preloaded RC beams strengthened with CFRP laminates.” J. Zhejiang Univ. Sci. A, 7(3), 436–444.
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© 2014 American Society of Civil Engineers.
History
Received: Nov 14, 2013
Accepted: Mar 11, 2014
Published online: May 7, 2014
Discussion open until: Oct 7, 2014
Published in print: Feb 1, 2015
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