Behavior of Prestressed Hollow-Core Slabs Strengthened in Flexure with Near-Surface Mounted Carbon Fiber-Reinforced Polymer Reinforcement
Publication: Journal of Composites for Construction
Volume 20, Issue 6
Abstract
Flexural strengthening of reinforced concrete using near-surface mounted (NSM) fiber-reinforced polymer (FRP) composites is a widely studied topic, and a promising technology. However, overlooked applications such as prestressed concrete and one-way slabs require further experimental investigation and theoretical refinement in order to develop comprehensive design guidelines. This paper investigates the behavior of prestressed hollow-core slabs strengthened in flexure with NSM carbon FRP strip reinforcement. Seven full-scale simply supported slab specimens were tested to failure under two-point monotonic load configuration. Experimental variables included two different internal prestressing reinforcement ratios, and three different NSM strengthening reinforcement ratios. This paper examines cracking behavior and modes of failure, load-strain relationships, deflections, and strengthened capacities. Also, a comparison between experimental results and theoretical predictions by relevant Canadian and American standards or guidelines is presented.
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Acknowledgments
The authors wish to express their gratitude and sincere appreciation for the financial support received from the Natural Science and Engineering Research Centre (NSERC) through the Canada Research Chair Program (CRC). In addition, a sincere thank-you goes to the technical staff at the University of Manitoba’s W.R. McQuade Structures Laboratory, Tetra Tech Inc., Lafarge Canada Inc., and Vector Construction Ltd. for their continued support and in-kind contributions.
References
ACI (American Concrete Institute). (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440.2R-08, Detroit.
ACI (American Concrete Institute). (2014). “Building code requirements for reinforced concrete.” ACI 318-14, Detroit.
Badawi, M., and Soudki, K. (2009). “Flexural strengthening of RC beams with prestressed NSM CFRP rods—Experimental and analytical investigation.” Constr. Build. Mater., 23(10), 3292–3300.
Bencardino, F., Spadea, G., and Swamy, R. N. (2002). “Strength and ductility of reinforced concrete beams externally reinforced with carbon fiber fabric.” ACI Struct. J., 99(2), 163–171.
Bonaldo, E., de Barros, J. A. O., and Lourenco, P. B. (2008). “Efficient strengthening technique to increase the flexural resistance of existing RC slabs.” J. Compos. Constr., 149–159.
CPCI (Canadian Precast/Prestressed Concrete Institute). (2007). Design manual-precast and prestressed concrete, Ottawa.
CSA (Canadian Standards Association). (2009). “Concrete materials and methods of concrete construction/test methods and standard practices for concrete.” CSA A23.1-09/A23.2-09 (R2014), Rexdale, ON, Canada, 647.
CSA (Canadian Standards Association). (2012). “Design and construction of building components with fiber-reinforced polymers.” CAN/CSA-S806-12, Toronto, 187.
CSA (Canadian Standards Association). (2014). “Code for the design of concrete structures for buildings.” CSA/A23.3-14, Rexdale, ON, Canada.
De Lorenzis, L., and Nanni, A. (2002). “Bond between near-surface mounted fiber-reinforced polymer rods and concrete in structural strengthening.” ACI Struct. J., 99(2), 123–132.
De Lorenzis, L., and Teng, J. G. (2006). “Near-surface mounted FRP reinforcement: An emerging technique for strengthening structures.” Compos. Part B: Eng., 38(2), 119–143.
Elgabbas, F., El-Ghandour, A. A., Abdelrahman, A. A., and El-Dieb, A. S. (2009). “Different CFRP strengthening techniques for prestressed hollow core concrete slabs: Experimental study and analytical investigation.” Compos. Struct., 92(2), 401–411.
El-Hacha, R., and Rizkalla, S. H. (2004). “Near-surface-mounted fiber-reinforced polymer reinforcements for flexural strengthening of concrete structures.” ACI Struct. J., 101(5), 717–726.
Hajihashemi, A., Mostofinejad, D., and Azhari, M. (2011). “Investigation of RC beams strengthened with prestressed NSM CFRP laminates.” J. Compos. Constr., 887–895.
Hassan, T. K., and Rizkalla, S. H. (2004). “Bond mechanism of near-surface-mounted fiber-reinforced polymer bars for flexural strengthening of concrete structures.” ACI Struct. J., 101(6), 830–839.
Hosny, A., Sayed-Ahmed, E. Y., Abdelrahman, A. A., and Alhlaby, N. A. (2006). “Strengthening precast-prestressed hollow core slabs to resist negative moments using carbon fiber reinforced polymer strips: An experimental investigation and a critical review of Canadian Standards Association S806-02.” Can. J. Civ. Eng., 33(8), 955–967.
Oudah, F., and El-Hacha, R. (2012). “A new ductility model of reinforced concrete beams strengthened using fiber reinforced polymer reinforcement.” Compos. Part B, 43(8), 3338–3347.
Teng, J. G., De Lorenzis, L., Wang, B., Li, R., Wong, T. N., and Lam, L. (2006). “Debonding failures of RC beams strengthened with near surface mounted CFRP strips.” J. Compos. Constr., 92–105.
Yost, J. R., Gross, S. P., Dinehart, D. W., and Mildenberg, J. J. (2007). “Flexural behavior of concrete beams strengthened with near-surface-mounted CFRP strips.” ACI Struct. J., 104(4), 430–437.
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Published In
Journal of Composites for Construction
Volume 20 • Issue 6 • December 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Oct 18, 2015
Accepted: Jan 22, 2016
Published online: Apr 1, 2016
Discussion open until: Sep 1, 2016
Published in print: Dec 1, 2016
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