Nonlaminated FRP Strap Elements for Reinforced Concrete, Timber, and Masonry Applications
Publication: Journal of Composites for Construction
Volume 15, Issue 2
Abstract
Advances in material technology allow for the exploration of new structural forms and systems. In recent years, fiber-reinforced polymers (FRPs) have emerged as candidate materials for civil engineering applications, and the use of FRPs in construction has been an area of growing interest. Unidirectional high-strength FRPs are well-suited for use as tensioning elements, but anchorage details present a challenge. An alternative is to self-anchor the FRP tensioning element by winding thin layers of material around supports and then laminating all the layers together (a laminated strap) or by securing only the outermost layer to form a closed outer loop while the inner layers remain nonlaminated (a nonlaminated strap). Nonlaminated FRP straps have been found to have higher efficiencies than equivalent laminated straps, which is advantageous in high-tension applications. The suitability of nonlaminated FRP straps for use as unbonded tension elements provides scope for use in new construction and for the strengthening of existing structures. A review of nonlaminated carbon FRP strap system properties and applications in the context of reinforced concrete, timber, and masonry structures is presented.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The majority of the work described in this paper has been realised, in part or in whole, as a direct result of Professor Urs Meier’s vision, support, and technical excellence. The authors consider it to be a great honor to have the opportunity to convey to a wider audience a mere glimpse of some of Professor Meier’s tremendous achievements in the development and application of high-strength tensile CFRP elements.
References
Bauersfeld, D. W. (1984). “Composite graphite/epoxy tensile element.” Report 2404, United States Army, Belvoir Research & Development Center, Fort Belvoir, VA, 1–64.
Brönnimann, R., and Widmann, R. (2009). “Monitoring a bowstring arch bridge at Empa with novel sensing systems.” Proc., 4th Int. Conf. on Structural Health Monitoring of Intelligent Infrastructure, U. Meier, B. Havranek and M. Motavalli, eds., SHMII, Dubendorf, Switzerland.
Conen, H. (1966). “Deformation und versagen von GFK-strangschlaufen.” Kautschuk + Gummi Kunststoffe, 56(9), 629–681 (in German).
Czaderski, C., Motavalli, M., and Winistörfer, A. (2008). “Prestressed shear strengthening of a box girder bridge with non-laminated CFRP straps.” Proc., 4th Int. Conf. on FRP Composites in Civil Engineering (CICE2008), M. Motavalli, ed.
Hoult, N. A. (2005). “Retrofitting of reinforced concrete beams with CFRP straps to enhance shear capacity.” Ph.D. thesis, Univ. of Cambridge, Cambridge, UK.
Hoult, N. A., and Lees, J. M. (2005). “Long-term performance of a CFRP strap shear retrofitting system.” 7th Int. Symp. on Fiber Reinforced Polymer for Reinforced Concrete Structures (FRPRCS-7), SP-230-40, C. K. Shield, J. P. Busel, S. L. Walkup, and D. D. Gremel, eds., ACI, Farmington Hills, MI, 685–704.
Hoult, N. A., and Lees, J. M. (2009). “Efficient CFRP strap configurations for the shear strengthening of reinforced concrete T-beams.” J. Compos. Constr., 13(1), 45–52.
Huster, U., Brönnimann, R., and Winistörfer, A. (2008). “Strengthening of a historical roof structure with CFRP straps.” Proc., 4th Int. Conf. on FRP Composites in Civil Engineering (CICE2008), M. Motavalli, ed.
Janke, L., Czaderski, C., Ruth, J., and Motavalli, M. (2009). “Experiments on the residual load-bearing capacity of prestressed confined concrete columns.” Eng. Struct., 31(10), 2247–2256.
Kesse, G., and Lees, J. M. (2007). “Experimental behaviour of reinforced concrete beams strengthened with prestressed CFRP shear straps.” J. Compos. Constr., 11(4), 375–383.
Lees, J. M., Winistörfer, A. U., and Meier, U. (2002). “External prestressed CFRP straps for the shear enhancement of concrete.” J. Compos. Constr., 6(4), 249–256.
Meier, U. (1992). “Carbon fiber-reinforced polymers: Modern materials in bridge engineering.” Struct. Eng. Int., 2(1), 7–12.
Meier, U. (1995). “Strengthening of structures using carbon fibre/epoxy composites.” Constr. Build. Mater., 9(6), 341–351.
Meier, U. (2000). “Composite materials in bridge repair.” Appl. Compos. Mater., 7, 75–94.
Meier, U. (2001). “Strengthening and stiffening of historic wooden structures with CFRP.” Proc., FRP Composites in Civil Engineering (CICE 2001), II, J. G. Teng, ed., 967–974.
Meier, U., and Winistörfer, A. (1995). “Retrofitting of structures through external bonding of CFRP sheets.” Non-metallic (FRP) reinforcement for concrete structures, L. Taerwe, ed., E&FN Spon, London, 465–472.
Mottram, J. T., and Turvey, G. J. (2003). “Physical test data for the appraisal of design procedures for bolted joints in pultruded FRP structural shapes and systems.” Prog. Struct. Eng. Mater., 5(4), 195–222.
Nägeli, R. (2006). “Evaluation of support pads for the shear enhancement of reinforced concrete.” Master’s project, ETH, Zürich.
Nanni, A., Bakis, C. E., O’Neil, E. F., and Dixon, T. O. (1996). “Short-term sustained loading of FRP tendon-anchor systems.” Constr. Build. Mater., 10(4), 255–266.
Niemann, R. C., et al. (1980). “Ultimate strength, low stress creep characteristics and thermal intercept methods for an epoxy fiberglass tension member support.” Adv. Cryog. Eng., 26, 300–308.
Pfyl-Lang, K., Huth, O., Green, M. F., and Motavalli, M. (2008). “Square RC columns confined with non-laminated CFRP straps.” Proc., 4th Int. Conf. on FRP Composites in Civil Engineering (CICE2008), M. Motavalli, ed.
Reed, R. P., and Golda, M. (1997). “Cryogenic composite supports: A review of strap and strut properties.” Cryogenics, 37(5), 233–250.
Schlaich, M., and Bleicher, A. (2007). “Spannbandbrücke mit Kohlenstofffaser-Lamellen.” Bautechnik, 84(Heft 5), 311–319 (in German).
Stenger, F. (2000). “Tragverhalten von Stahlbetonscheiben mit vorgespannter externer Kohlenstoffaser-Schubbewehrung.” Ph.D. thesis, ETH Zurich (in German).
Stenger, F. (2003). “Tragverhalten von Stahlbetonscheiben mit vorgespannter externer Schubbewehrung aus Kohlenstoffasern.” CFK in Bauwesen—heute Realität, Empa Akademie, 59–67 (in German).
Triantafillou, T. C., and Fardis, M. N. (1997). “Strengthening of historic masonry structures with composite materials.” Mater. Struct., 30, 486–496.
Winistörfer, A. U. (1999). “Development of non-laminated advanced composite straps for civil engineering applications.” Ph.D. thesis, University of Warwick, UK.
Winistörfer, A., Meier, U., and Lees, J. M. (2001). “CARBOSTRAP- Advanced composite tendons.” Proc., ACUN-3, Technology Convergence in Composites Applications, S. Bandyopadhyay, N. Gowripalan, and N. Drayton, eds., Sydney, Australia, 24–30.
Winistörfer, A., and Mottram, J. T. (1997). “The future of pin-loaded straps in civil engineering applications.” Recent advances in bridge engineering, U. Meier and R. Betti, eds., Empa, Switzerland, 115–120.
Winistörfer, A., and Mottram, J. T. (2001). “Finite element analysis of non-laminated composite pin-loaded straps for civil engineering.” J. Compos. Mater., 35(7), 577–602.
Yapa, H. D., and Lees, J. M. (2009). “Optimum shear strengthening of reinforced concrete beams with prestressed carbon fibre reinforced polymer (CFRP) straps.” Proc., 4th Advanced Composites in Construction (ACIC 09), S. Halliwell and C. Whysall, eds., NetComposites, 214–226.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 15 • Issue 2 • April 2011
Pages: 146 - 155
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Oct 6, 2009
Accepted: May 4, 2010
Published online: May 11, 2010
Published in print: Apr 1, 2011
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.