Near-Surface-Mounted Composite System for Repair and Strengthening of Reinforced Concrete Columns Subjected to Axial Load and Biaxial Bending
Publication: Journal of Composites for Construction
Volume 15, Issue 4
Abstract
This paper aims to examine the effectiveness of near-surface-mounted (NSM) glass fiber-reinforced polymer (GFRP) composite rebars in combination with external confinement with carbon fiber-reinforced polymer (CFRP) composite sheets to repair and strengthen reinforced concrete (RC) columns exposed to axial load and biaxial bending. Nine columns with a square cross section of were constructed and tested under biaxial eccentric loading with equal eccentricity along each principal axis. Test parameters included load eccentricity, concrete grade, and level of the CFRP confinement used in combination with the NSM-GFRP reinforcement. The effectiveness of the NSM-GFRP reinforcement was greatly affected by the CFRP-confinement level and the load eccentricity. For columns with a high level of CFRP confinement, the gain in the load capacity attributable to the NSM-GFRP reinforcement was higher at a lower eccentricity. For columns with a low level of CFRP confinement, the gain in the load capacity attributable to the NSM-GFRP reinforcement was higher at a higher eccentricity. The enhancement in the load capacity was more pronounced in the columns with a lower concrete grade. An analytical model for predicting the load capacity of RC columns strengthened with NSM-GFRP rebars in combination with CFRP confinement under axial load and biaxial bending is introduced. The model accounts for the nonlinear behavior of materials and the change in geometry under biaxial eccentric loading. The model accuracy is demonstrated by comparing the model predictions with the experimental results.
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Acknowledgments
The authors would like to express their appreciation to the Research Affairs at the UAE-University for the financial support for this project under Grant No. UNSPECIFIED01-01-7-11/09. The authors would like to thank Dr. Salwan Al-Assafi, general manager of Pultron Composites Middle East, for donating the GFRP rebars. Thanks are also due to the laboratory specialist, Eng. Tarek Salah, the assistantlaboratory specialist, Mr. Faisel Abdel-Wahab, and the undergraduate research assistants, Hothifa Rajoub and Anes Bouchair, for their help throughout the testing.
References
American Concrete Institute (ACI). (2005). “Building code requirements for structural concrete.” ACI 318-05, Farmington Hills, MI.
American Concrete Institute (ACI). (2008a). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440.2R, Farmington Hills, MI.
American Concrete Institute (ACI). (2008b). “Self-compacting concrete, manual for concrete practice.” ACI 237R, Farmington Hills, MI.
Balaguru, P., Nanni, A., and Giancaspro, J. (2009). FRP composites for reinforced and prestressed concrete structures, Taylor & Francis, New York.
Bank, L. (2006). Composites for construction: Structural design with FRP materials, Wiley, Hoboken, NJ.
Barros, J., Ferreira, D., Fortes, A., and Dias, S. (2006). “Assessing the effectiveness of embedding CFRP laminates in the near surface for structural strengthening.” Constr. Build. Mater., 20(7), 478–491.
Barros, J., and Fortes, A. (2005). “Flexural strengthening of concrete beams with CFRP laminates bonded into slits.” Cem. Concr. Compos., 27(4), 471–480.
Bournas, D., and Triantafillou, T. (2009). “Strengthening of reinforced concrete columns with near-surface-mounted FRP or stainless steel.” ACI Struct. J., 106(4), 495–505.
Chaallal, O., and Shahawy, M. (2000). “Performance of fiber-reinforced polymer-wrapped reinforced concrete columns under combined axial-flexural loading.” ACI Struct. J., 97(4), 659–669.
Eid, R., Roy, N., and Paultre, P. (2009). “Normal- and high-strength concrete circular elements wrapped with FRP composites.” J. Compos. Constr., 13(2), 113–124.
El-Hacha, R., and Rizkalla, S. (2004). “Near-surface-mounted fiber-reinforced polymer reinforcements for flexural strengthening of concrete structures.” ACI Struct. J., 101(5), 717–726.
El-Maaddawy, T. (2009). “Strengthening of eccentrically loaded reinforced concrete columns with FRP wrapping system: Experimental investigation and analytical modeling.” J. Compos. Constr., 13(1), 13–24.
El-Sayed, M., and El-Maaddawy, T. (2010). “Analytical model for prediction of the load capacity of RC columns confined with CFRP under uniaxial and biaxial eccentric loading.” Mater. Struct., 44(1), 299–311.
El-Maaddawy, T., El-Sayed, M., and Abdel-Magid, B. (2010). “The effects of cross-sectional shape and loading condition on performance of reinforced concrete members confined with carbon fiber-reinforced polymers.” Mater. Des., 31(5), 2330–2341.
European Federation for Specialist Construction Chemicals and Concrete Systems (EFNARC). (2005). Specifications and guidelines for self-compacting concrete, English Ed., Warrington, UK.
Ghosh, K., and Sheikh, S. (2007). “Seismic upgrade with carbon fiber-reinforced polymer of columns containing lap-spliced reinforcing bars.” ACI Struct. J., 104(2), 227–236.
Hadi, M. (2006). “Behaviour of FRP wrapped normal strength concrete columns under eccentric loading.” Compos. Struct., 72(4), 503–511.
Hognestad, E., Hanson, N., and McHenry, D. (1955). “Concrete stress distribution in ultimate strength design.” J. Am. Concr. Inst., 52(6), 455–479.
Hollaway, L., and Teng, J. (2008). Strengthening and rehabilitation of civil infrastructure using fibre-reinforced polymer (FRP) composites, Woodhead, Oxford, UK.
Jiang, T., and Teng, J. (2009). “Slender FRP-confined circular RC columns.” Proc., 9th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-9), ICE, Melbourne, Australia.
Lam, L., and Teng, J. (2003). “Design-oriented stress-strain model for FRP-confined concrete.” Constr. Build. Mater., 17(6–7), 471–489.
Lignola, G., Prota, A., Manfredi, G., and Cosenza, E. (2007). “Experimental performance of RC hollow columns confined with CFRP.” J. Compos. Constr., 11(1), 42–49.
Mukherjee, A., Boothby, T., Bakis, C., Joshi, M., and Maitra, S. (2004). “Mechanical behavior of fiber-reinforced polymer-wrapped concrete columns: complicating effects.” J. Compos. Constr., 8(2), 97–103.
Parvin, A., and Schroeder, J. (2008). “Investigation of eccentrically loaded CFRP-confined elliptical concrete columns.” J. Compos. Constr., 12(1), 93–101.
Parvin, A., and Wang, W. (2001). “Behavior of FRP jacketed concrete columns under eccentric loading.” J. Compos. Constr., 5(3), 146–152.
Punurai, W., Chen, J., and Hsu, C. (2009). “RC slender columns strengthened by CFRP composite fabrics subjected to biaxial bending and axial compression.” Proc., 9th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-9).
Ranger, M., and Bisby, L. (2007). “Effects of load eccentricities on circular FRP confined reinforced concrete columns.” Proc., 8th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-8), Univ. of Patras, Patras, Greece.
Rocca, S., Galati, N., and Nanni, A. (2008). “Review of design guidelines for FRP confinement of reinforced concrete columns of noncircular cross-sections.” J. Compos. Constr., 12(1), 80–92.
Sause, R., Harries, K., Walkup, S., Pessiki, S., and Ricles, J. (2004). “Flexural behavior of concrete columns retrofitted with carbon fiber-reinforced polymer jackets.” ACI Struct. J., 101(5), 708–716.
Wu, H., Wang, Y., Yu, L., and Li, X. (2009). “Experimental and computational studies on high-strength concrete circular columns confined by aramid fiber-reinforced polymer sheets.” J. Compos. Constr., 13(2), 125–134.
Yi, W., Xian, Q., Ding, H., and Zhang, H. (2004). “Experimental study of RC columns strengthened with CFRP sheets under eccentric compression.” ACI Spec. Pub., 238, 395–410.
Yost, J., Gross, S., Dinehart, D., and Mildenberg, J. (2007). “Flexural behavior of concrete beams strengthened with near-surface-mounted CFRP strips.” ACI Struct. J., 104(4), 430–437.
Youcef, Y., Amziane, S., and Chemrouk, M. (2008). “The influence of CFRP on the behavior of reinforced concrete subjected to buckling.” Proc., 4th Int. Conf. on FRP Composites in Civil Engineering (CICE 2008), EMPA, Zürich, Switzerland.
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Published In
Journal of Composites for Construction
Volume 15 • Issue 4 • August 2011
Pages: 602 - 614
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Apr 14, 2010
Published online: Oct 1, 2010
Accepted: Oct 18, 2010
Published in print: Aug 1, 2011
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