FRP Retrofit of Low and Medium Strength Circular and Rectangular Reinforced Concrete Columns
Publication: Journal of Materials in Civil Engineering
Volume 20, Issue 2
Abstract
In this study, 68 reinforced concrete columns were tested under uniaxial compression after being jacketed externally with carbon fiber-reinforced polymer (CFRP) sheets. Forty specimens were cast using low strength concrete and inadequate internal transverse reinforcement, while 28 specimens were cast with medium strength concrete and adequate internal transverse reinforcement. Thickness of the CFRP jacket, cross-section shape, concrete strength, amount of internal transverse reinforcement, corner radius, existence of predamage, loading type (monotonic or cyclic), and the bonding pattern (orientation, spacing, anchorage details, additional corner supports) of CFRP sheets were the main test parameters of this extensive experimental work. Test results showed that external confinement of columns with CFRP sheets resulted in an increase in ultimate strength and ductility. While the strength enhancement was more pronounced for specimens with circular cross section, specimens with square and rectangular cross sections exhibited larger ultimate axial deformations without a substantial loss in strength. The efficiency of retrofitting was much more pronounced in the case of relatively lower strength concrete. The proposed model, together with two other available models, were used for predicting the strength and corresponding axial deformations of more than 300 specimens tested by other researchers, as well as more than 100 specimens tested by the writers during this study and before. It was shown that the predicted results by the proposed model were in reasonable agreement with this extensive database of experimental studies.
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Acknowledgments
The writers wish to thank Basf Turkey Company, Set Italcementi Group, Mr. T. Pala, Mr. B. Turgut, and Mr. M. Tiryaki for their contributions during the preparations of the specimens. A part of this study is supported by the European Union through Lessloss Project. The assistance of Mr. V. Koc and Mr. E. Yilmaz during the experiments is also acknowledged.EU
References
Aire, C., Gettu, R., and Casas, J. R. (2001). “Study of the compressive behavior of concrete confined by fiber reinforced composites.” Proc., Int. Conf. on Composites in Construction, Porto, Portugal, 239–243.
American Concrete Institute (ACI). (2002). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440, Detroit, Mich.
Arduini, M., Di Tommaso, A., Manfroni, O., Ferrari, S., and Romagnolo, M. (1999). “Il confinamento passivo di elementi compressi in calcestruzzo con fogli in materiale composito.” L’Industria Italiana del Cemento, 11, 836–841.
Au, C., and Buyukozturk, O. (2005). “Effect of fiber orientation and ply mix on fiber reinforced polymer-confined concrete.” J. Compos. Constr., 9(5), 397–407.
Becque, J., Patnaik, A. K., and Rizkalla, S. H. (2003). “Analytical models for concrete confined with FRP tubes.” J. Compos. Constr., 7(1), 31–38.
Bisby, L. A., Dent, A. J. S., and Green, M. F. (2005). “Comparison of confinement models for fiber-reinforced polymer-wrapped concrete.” ACI Struct. J., 102(1), 62–72.
Bousias, S. N., Triantafillou, T. C., Fardis, M. N., and Spathis, L. (2004). “Fiber-reinforced polymer retrofitting of rectangular reinforced concrete columns with or without corrosion.” ACI Struct. J., 101(4), 512–520.
Campione, G. (2006). “Influence of FRP wrapping techniques on the compressive behavior of concrete prisms.” Cem. Concr. Compos., 28, 497–505.
Canadian Standards Association (CSA). (2002). “Design and construction of building components with fiber-reinforced polymers.” CAN/CSA-S806, Ottawa, Canada.
Chaallal, O., Hassan, M., and LeBlanc, M. (2006). “Circular columns confined with FRP: Experimental versus predictions of models and guidelines.” J. Compos. Constr., 10(1), 4–12.
CNR—Advisory Committee on Technical Recommendations for Constructions. (2004). “Guide for the design and construction of externally bonded FRP systems for strengthening existing structures.” CNR-DT 200/2004, Rome, Italy.
Comite Européen de Normalisation (CEN). (2005). “Assessment and retrofitting of buildings.” EN 1998-3: Eurocode 8 Part 3, Brussels, Belgium.
De Lorenzis, L., and Tepfers, R. (2003). “Comparative study of models on confinement of concrete cylinders with fiber-reinforced polymer composites.” J. Compos. Constr., 7(3), 219–237.
Demers, M., and Neale, K. W. (1994). “Strengthening of concrete columns with unidirectional composite sheets.” Development in Short and Medium Span Bridge Engineering ’94, Proc. of the 4th Int. Conf. on Short and Medium Span Bridges, A. A. Mufti, B. Bakht, and L. G. Jaeger, eds., Canadian Society for Civil Engineering, Montreal, 895–905.
Demers, M., and Neale, K. W. (1999). “Confinement of reinforced concrete columns with fibre-reinforced composite sheets—An experimental study.” Can. J. Civ. Eng., 26(2), 226–241.
Dias da Silva, V., and Santos, J. M. C. (2001). “Strengthening of axially loaded concrete cylinders by surface composites.” Proc., Int. Conf. on Composites in Construction, Porto, Portugal, 257–262.
Fam, A. Z., and Rizkalla, S. H. (2001). “Confinement model for axially loaded concrete confined by circular fiber-reinforced polymer tubes.” ACI Struct. J., 98(4), 451–461.
Fédération Internationale du Béton (fib). (2001). “Externally bonded FRP reinforcement for rc structures.” Technical Rep., Bulletin No. 14.
Fédération Internationale du Béton (fib). (2006). “Retrofitting of concrete structures by externally bonded FRPs.” Technical Rep., Bulletin No. 35.
Hadi, N. S. (2006). “Comparative study of eccentrically loaded FRP wrapped columns.” Compos. Struct., 74, 127–135.
Harajli, M. H. (2006). “Axial stress-strain relationship for FRP confined circular and rectangular concrete columns.” Cem. Concr. Compos., 28, 938–948.
Harries, K. A., Kestner, J., Pessiki, S., Sause, R., and Ricles, J. (1998). “Axial behavior of reinforced concrete columns retrofit with FRPC jackets.” Proc., 2nd Int. Conf. on Composites in Infrastructures, H. Saadatmanesh and M. R. Ehsani, eds., Tucson, Ariz., 411–425.
Hollaway, L. C. (2003). “The evolution of the way forward for advanced polymer composites in the civil infrastructure.” Constr. Build. Mater., 17, 365–378.
Howie, I., and Karbhari, V. M. (1994). “Effect of materials architecture on strengthening efficiency of composite wraps for deteriorating columns in the Northeast.” Infrastructure: New Materials and Methods of Repair, Proc., 3rd Materials Engineering Conf., K. D. Basham, ed., Material Engineering Division, ASCE, New York, 199–206.
Ilki, A. (2006). “FRP strengthening of RC columns (shear, confinement and lap splices).” fib bulletin No. 35: Retrofitting of concrete structures by externally bonded FRPs, G. L. Balazs and M. Fardis, eds., Lausanne, Switzerland, 123–142.
Ilki, A., Koc, V., Peker, O., Karamuk, E., and Kumbasar, N. (2004a). “Strengthening of RC columns with inadequate transverse reinforcement.” Proc., Second Int. Conf. on FRP Composites in Civil Engineering, Adelaide, Australia, 211–218.
Ilki, A., and Kumbasar, N. (2002). “Behavior of damaged and undamaged concrete strengthened by carbon fiber composite sheets.” Struct. Eng. Mech., 13(1), 75–90.
Ilki, A., and Kumbasar, N. (2003). “Compressive behaviour of carbon fibre composite jacketed concrete with circular and noncircular cross-sections.” J. Earthquake Eng., 7(3), 381–406.
Ilki, A., Kumbasar, N., and Koc, V. (2004b). “Low strength concrete members externally confined with FRP sheets.” Struct. Eng. Mech., 18(2), 167–194.
Ilki, A., Kumbasar, N., Ozdemir, P., and Fukuta, T. (2004c). “A trilinear stress-strain model for confined concrete.” Struct. Eng. Mech., 18(5), 541–563.
Ilki, A., Peker, O., Karamuk, E., and Kumbasar, N. (2006). “External confinement of low strength brittle reinforced concrete short columns.” Proc., ACI SP-238, Int. Symp. on Confined Concrete, Y. Xiao, S. Kunnath, and W. Yi, eds., Farmington Hills, Mich., 363–380.
Japan Society of Civil Engineers (JSCE). (2001). “Recommendations for upgrading of concrete structures with use of continuous fibre sheet.” Concrete Engineering Series, No. 41.
Karantzikis, M., Papanicolaou, C. G., Antonopoulos, C. P., and Triantafillou, T. C. (2005). “Experimental investigation of nonconventional confinement for concrete using FRP.” J. Compos. Constr., 9(6), 480–487.
Karbhari, V. M., and Gao, Y. (1997). “Composite jacketed concrete under uniaxial compression—Verification of simple design equations.” J. Mater. Civ. Eng., 9(4), 185–193.
Kshirsagar, S., Lopez-Anido, R. A., and Gupta, R. K. (2000). “Environmental aging of fiber-reinforced polymer-wrapped concrete cylinders.” ACI Mater. J., 97(6), 703–712.
Lam, L., and Teng, J. G. (2002). “Strength models for fiber-reinforced plastic-confined concrete.” J. Struct. Eng., 128(5), 612–623.
Lam, L., and Teng, J. G. (2003a). “Design-oriented stress-strain model for FRP-confined concrete.” Constr. Build. Mater., 17, 471–489.
Lam, L., and Teng, J. G. (2003b). “Design-oriented stress-strain model for FRP-confined concrete in rectangular columns.” J. Reinf. Plast. Compos., 22(13), 1149–1186.
Lam, L., and Teng, J. G. (2004). “Ultimate condition of fiber reinforced polymer-confined concrete.” J. Compos. Constr., 8(6), 539–548.
Lam, L., Teng, J. G., Cheung, C. H., and Xiao, Y. (2004). “Behavior of FRP-confined concrete under cyclic axial compression.” Proc., Int. Symp. on Confined Concrete (CD-ROM), Changsha, China.
Lam, L., Teng, J. G., Cheung, C. H., and Xiao, Y. (2006). “FRP-confined concrete under axial cyclic compression.” Cem. Concr. Compos., 28, 949–958.
Li, G. (2006). “Experimental study of FRP confined concrete cylinders.” Eng. Struct., 28, 1001–1008.
Li, G., Maricherla, D., Singh, K., Pang, S., and John, M. (2006). “Effect of orientation on the structural behavior of FRP wrapped concrete cylinders.” Compos. Struct., 74, 475–483.
Lin, H., and Liao, C. (2004). “Compressive strength of reinforced concrete column confined by composite material.” Compos. Struct., 65(2), 239–250.
Mandal, S., Hoskin, A., and Fam, A. (2005). “Influence of concrete strength on confinement effectiveness of fiber-reinforced polymer circular jackets.” ACI Struct. J., 102(3), 383–392.
Mander, J. B., Priestley, M. J. N., and Park, R. (1988). “Theoretical stress-strain model for confined concrete.” J. Struct. Eng., 114(8), 1804–1826.
Matthys, L., Taerwe, L., and Audenaert, K. (1999). “Tests on axially loaded concrete columns confined by fiber reinforced polymer sheet wrapping.” Fiber reinforced polymer reinforcement for reinforced concrete structures, ACI SP-188, C. W. Dolan, S. H. Rizkalla, and A. Nanni, eds., American Concrete Institute, Detroit, 217–228.
Matthys, S., Toutanji, H., Audenaert, K., and Taerwe, L. (2005). “Axial load behavior of large-scale columns confined with fiber-reinforced polymer composites.” ACI Struct. J., 102(2), 258–267.
Matthys, S., Toutanji, H., and Taerwe, L. (2006). “Stress-strain behavior of large-scale circular columns confined with FRP composites.” J. Struct. Eng., 132(1), 123–133.
Mirmiran, A., Bank, L. C., Neale, K. W., Mottram, J. T., Ueda, T., and Davalos, J. F. (2003). “World survey of civil engineering programs on fiber reinforced polymer composites for construction.” J. Profl. Issues Eng. Educ. Pract., 129(3), 155–160.
Mirmiran, A., Shahawy, M., Samaan, M., El Echary, H., Mastrapa, J. C., and Pico, O. (1998). “Effect of column parameters on FRP-confined concrete.” J. Compos. Constr., 2(4), 175–185.
Mirmiran, A., Zagers, K., and Yuan, W. (2000). “Nonlinear finite element modeling of concrete confined by fiber composites.” Finite Elem. Anal. Design, 35, 79–96.
Miyauchi, K., Inoue, S., Kuroda, T., and Kobayashi, A. (1999). “Strengthening effects of concrete columns with carbon fiber sheet.” Trans. Jpn. Concr. Inst., 21, 143–150.
Nanni, A. (2003). “North American design guidelines for concrete reinforcement and strengthening using FRP: Principles, applications and unresolved issues.” Constr. Build. Mater., 17, 439–446.
Nanni, A., and Bradford, N. M. (1995). ‘FRP jacketed concrete under uniaxial compression.” Constr. Build. Mater., 9(2), 115–124.
Parvin, A., and Wang, W. (2001). “Behaviour of FRP jacketed concrete columns under eccentric loading.” J. Compos. Constr., 5, 146–152.
Pessiki, S., Harries, K. A., Kestner, J. T., Sause, R., and Ricles, J. R. (2001). “Axial behavior of reinforced concrete columns confined with FRP jackets.” J. Compos. Constr., 5(4), 237–245.
Picher, F., Rochette, P., and Labossiere, P. (1996). “Confinement of concrete cylinders with CFRP.” Proc., First Int. Conf. on Composites for Infrastructures, Tucson, Ariz., Jan. 15–17, 829–841.
Purba, B. K., and Mufti, A. A. (1999). “Investigation of the behavior of circular concrete columns reinforced with carbon fiber reinforced polymer (CFRP) jackets.” Can. J. Civ. Eng., 26, 590–596.
Rocca, S., Galati, N., and Nanni, A. (2006). “Large-size reinforced concrete columns strengthened with carbon FRP: Experimental evaluation.” Proc., Third Int. Conf. on FRP Composites in Civil Engineering, Miami, Fla., 491–494.
Rochette, P., and Labossiere, P. (2000). “Axial testing of rectangular column models confined with composites.” J. Compos. Constr., 4(3), 129–136.
Saafi, M., Toutanji, H., and Li, Z. (1999). “Behavior of concrete columns confined with fiber reinforced polymer tubes.” ACI Mater. J., 96(4), 500–509.
Samaan, M., Mirmiran, A., and Shahawy, M. (1998). “Model of concrete confined by fiber composites.” J. Struct. Eng., 124(9), 1025–1031.
Scott, B. D., Park, R., and Priestley, M. J. N. (1982). “Stress-strain behavior of concrete confined by overlapping hoops at low and high strain rates.” ACI J., 79(1), 13–27.
Shahawy, M., Mirmiran, A., and Beitelman, T. (2000). “Tests and modeling of carbon-wrapped concrete columns.” Composites, Part B, 31, 471–480.
Shao, Y. (2003). “Behavior of FRP-confined concrete beam-columns under cyclic loading.” Ph.D. thesis, North Carolina State Univ.
Shao, Y., Zhu, Z., and Mirmiran, A. (2006). “Cyclic modeling of FRP-confined concrete with improved ductility.” Cem. Concr. Compos., 28, 959–968.
Shehata, I. A. E. M., Carneiro, L. A. V., and Shehata, L. C. D. (2002). “Strength of short concrete columns confined with CFRP sheets.” Mater. Struct., 35(245), 50–58.
Silva, M. A. G., and Rodrigues, C. C. (2006). “Size and relative stiffness effects on compressive failure of concrete columns wrapped with glass FRP.” J. Mater. Civ. Eng., 18(3), 334–342.
Soudki, K. A., and Green, M. F. (1996). “Performance of CFRP retrofitted concrete columns at low temperatures.” Proc., 2nd Int. Conf. on Advanced Composite Materials in Bridges and Structures, Montreal, Quebec, 427–434.
Suter, R., and Pinzelli, R. (2001). “Confinement of concrete columns with FRP sheets.” Proc., 5th Int. Conf. on Fibre Reinforced Plastics for Reinforced Concrete Structures, Cambridge, U.K., 793–802.
Tan, K. H. (2002). “Strength enhancement of rectangular reinforced concrete columns using fiber-reinforced polymer.” J. Compos. Constr., 6(3), 175–183.
Tastani, S. P., and Pantazopoulou, S. J. (2004). “Experimental evaluation of FRP jackets upgrading RC corroded columns with substandard detailing.” Eng. Struct., 26, 817–829.
Tastani, S. P., Pantazopoulou, S. J., Zdoumba, D., Plakantaras, V., and Akritidis, E. (2006). “Limitations of FRP jacketing in confining old-type reinforced concrete members in axial compression.” J. Compos. Constr., 10(1), 13–25.
Toutanji, H. A. (1999). “Stress-strain characteristics of concrete columns externally confined with advanced fiber composite sheets.” ACI Mater. J., 96(3), 397–404.
Turkish seismic design code. (2006). Ministry of Public Works and Settlement.
Wang, P., and Cheong, K. K. (2001). “RC columns strengthened by FRP under uniaxial compression.” Proc., Int. Conf. on FRP Composites in Civil Engineering, Hong Kong, China, 327–334.
Wang, Y. C., and Restrepo, J. I. (2001). “Investigation of concentrically loaded reinforced concrete columns confined with glass fiber-reinforced polymer jackets.” ACI Struct. J., 98(3), 377–385.
Watanabe, K., et al. (1997). “Confinement effect of FRP sheet on strength and ductility of concrete cylinders under uniaxial compression.” Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Sapporo, Japan, 233–240.
Xiao, Y., and Wu, H. (2000). “Compressive behaviour of concrete confined by carbon fiber composite jackets.” J. Mater. Civ. Eng., 12(2), 139–146.
Yang, X., Wei, J., Nanni, A., and Dharani, L. R. (2004). “Shape effect on the performance carbon fiber reinforced polymer wraps.” J. Compos. Constr., 8(5), 444–451.
Zhang, S., Ye, L., and Mai, Y. W. (2000). “A study on polymer composite strengthening systems for concrete columns.” Appl. Compos. Mater., 7, 125–138.
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Published In
Journal of Materials in Civil Engineering
Volume 20 • Issue 2 • February 2008
Pages: 169 - 188
Copyright
© 2008 ASCE.
History
Received: Mar 9, 2007
Accepted: May 8, 2007
Published online: Feb 1, 2008
Published in print: Feb 2008
Notes
Note. Associate Editor: Kiang Hwee Tan
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