Axial Load Capacity of Concrete-Filled FRP Tube Columns: Experimental versus Theoretical Predictions
Publication: Journal of Composites for Construction
Volume 14, Issue 2
Abstract
This paper presents the experimental and theoretical results of small and medium-scale concrete-filled fiber-reinforced polymer (FRP) tube (CFFT) columns. A total of 23 CFFT specimens were tested under axial compression load. Five different types of new FRP tubes were used as stay-in-place formwork for the columns. The effects of the following parameters were examined: the FRP-confinement ratio, the unconfined concrete compressive strength, the presence of longitudinal steel reinforcement, and the height-to-diameter ratio. Comparisons between the experimental test results and the theoretical prediction values by the three North American codes and design guidelines (ACI 440.2R-08, CSA-S6-06, and CSA-S806-02) are performed in terms of confined concrete strength and ultimate load carrying capacity. The results of this investigation indicate that the design equations of the ACI 440.2R-08, CAN/CSA-S6-06, and CAN/CSA-S806-02 overestimate the factored axial load capacity of the short CFFT columns as compared to the yield and crack load levels. Also, the CAN/CSA-S6-06 and CAN/CSA-S806-02 confinement models showed conservative predictions, while the ACI 440.2R-08 was slightly less conservative. A new confinement model is proposed for the confined concrete compressive strength of the CFFT cylinders. Also, the design equations are modified to accurately predict the ultimate and yield load capacities of internally reinforced and unreinforced short CFFT columns. Two new factors are introduced in the modified equations, accounts for the in-place-strength of CFFT columns to CFFT cylinder strength, and accounts for the initiation of the steel yielding and concrete cracking for the FRP-confined columns.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The research reported in this paper was partially sponsored by the Natural Sciences and Engineering Research Council of Canada (NSERC). The writers also acknowledge the contribution of the Canadian Foundation for Innovation (CFI) for the infrastructure used to conduct testing. Special thanks to the manufacturer (FRE Composites, QC, Canada) for providing FRP tubes. The technician N. Simard participated in preparation of the specimens and conducting the tests.
References
American Concrete Institute (ACI). (2008a). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440.2R-08, Farmington Hills, Mich.
American Concrete Institute (ACI). (2008b). “Building code requirements for structural concrete.” ACI 318-08, Farmington Hills, Mich.
ASTM. (2008a). “Standard test method for apparent hoop tensile strength of plastic or reinforced plastic pipe by split disk method.” D2290-08, West Conshohocken, Pa.
ASTM. (2008b). “Standard test method for tensile properties of plastics.” D638-08, West Conshohocken, Pa.
ASTM. (2009). “Standard specification for deformed and plain carbon-steel bars for concrete reinforcement.” A615/A615M-09, West Conshohocken, Pa.
Benmokrane, B., El-Salakawy, E. F., El-Ragaby, A., and Lackey, T. (2006). “Designing and testing of concrete bridge decks reinforced with glass FRP bars.” J. Bridge Eng., 11(2), 217–229.
Bisby, L. A., Dent, J. S., and Green, M. F. (2005). “Comparison of confinement models for fibre-reinforced polymer-wrapped concrete.” ACI Struct. J., 102(4), 596–604.
Canadian Standard Association (CSA). (2002). “Design and construction of building components with fibre-reinforced polymers.” CSA-S806-02, Rexdale BD, Toronto.
Canadian Standard Association (CSA). (2006). “Canadian highway bridge design code.” CAN/CSA-S6-06, Toronto.
Carey, S. A., and Harries, K. A. (2005). “Axial behavior and modeling of confined small-, medium-, and large-scale circular sections with carbon fiber-reinforced polymer jackets.” ACI Struct. J., 102(1), 62–72.
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.
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, 226–241.
Fam, A., and Rizkalla, S. H. (2001a). “Confinement model for axially loaded concrete confined by circular fiber-reinforced polymer tubes.” ACI Struct. J., 98(4), 451–461.
Fam, A., and Rizkalla, S. H. (2001b). “Behavior of axially loaded concrete-filled circular fiber-reinforced polymer tubes.” ACI Struct. J., 98(3), 280–289.
Jaffry, S. A. D. (2001). “Concrete filled glass fibre reinforced polymer (GFRP) shells under concentric compression.” MSc thesis, Univ. of Toronto, Toronto.
Karbhari, V. M. (2004). “Fiber reinforced composite bridge systems-transition from the laboratory to the field.” Compos. Struct., 66, 5–16.
Karbhari, V. M., Seible, F., Burgueño, R., Davol, A., Wernli, M., and Zhao, L. (2000). “Structural characterization of fiber-reinforced composite short- and medium-span bridge systems.” Appl. Compos. Mater., 7(2–3), 151–182.
Kim, S. (2007). “Behavior of high-strength concrete columns.” Ph.D. thesis, North Carolina State Univ., Raleigh, N.C.
Lam, L., and Teng, J. G. (2003). “Design-oriented stress-strain model for FRP confined concrete.” Construct. Build. Mater., 17(6–7), 471–489.
Lam, L., and Teng, J. G. (2004). “Ultimate condition of FRP-confined concrete.” J. Compos. Constr., 8(6), 539–548.
Lyse, I., and Kreidler, C. L. (1932). “Fourth progress report on column tests at Lehigh University.” ACI J., 28, 317–346.
Masmoudi, R., Thériault, M., and Benmokrane, B. (1998). “Flexural behaviour of concrete beams reinforced with deformed fibre reinforced plastic reinforcing rods.” ACI Struct. J., 95(6), 665–676.
Mirmiran, A., Shahawy, M., Samaan, M., El Echary, H., Mastrapa, J. C., and Pico, O. (1998). “Effect of column parameters on FRP-confined column.” J. Compos. Constr., 2(4), 175–185.
Mohamed, H., and Masmoudi, R. (2008). “Compressive behaviour of reinforced concrete filled FRP tubes.” American Concrete Institute (ACI) special publications, SP-257–06, ACI, Farmington Hills, Mich., 91–108.
Ozbakkaloglu, T., and Saatcioglu, M. (2004). “Rectangular stress block for high-strength concrete.” ACI Struct. J., 101(4), 475–483.
Pessiki, S., Harries, K. A., Kestner, J. T., Sause, R., and Ricles, J. M. (2001). “Axial behavior of reinforced concrete columns confined with FRP jackets.” J. Compos. Constr., 5(4), 237–245.
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.
Saafi, M., Toutanji, H. A., 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.
Sheikh, S. A., Jaffry, S. A. D., and Cui, C. (2007). “Investigation of glass-fibre-reinforced-polymer shells as formwork and reinforcement for concrete columns.” Can. J. Civ. Eng., 34(3), 389–402.
Son, J. -K., and Fam, A. (2008). “Finite element modeling of hollow and concrete-filled fiber composite tubes in flexure: Model development, verification and investigation of tube parameters.” Eng. Structures, 30, 2656–2666.
Thériault, M., and Neale, K. W. (2000). “Design equations for axially loaded reinforced concrete columns strengthened with fibre reinforced polymer wraps.” Can. J. Civ. Eng., 27, 1011–1020.
Wu, G., Lu, Z. T., and Wu, Z. S. (2006). “Strength and ductility of concrete cylinders confined with FRP composites.” Construct. Build. Mater., 20, 134–148.
Yuan, W., and Mirmiran, A. (2001). “Buckling analysis of concrete-filled FRP tubes.” Int. J. Struct. Stab. Dyn., 1(3), 367–383.
Zhu, Z., Ahmad, I., and Mirmiran, A. (2005). “Effect of column parameters on axial compression behavior of concrete-filled FRP tube.” Adv. Struct. Eng., 8(4), 443–450.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 14 • Issue 2 • April 2010
Pages: 231 - 243
Copyright
© 2010 ASCE.
History
Received: Mar 13, 2009
Accepted: Aug 27, 2009
Published online: Mar 15, 2010
Published in print: Apr 2010
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.