Behavior of prestressed concrete I-girders strengthened in shear with externally bonded fiber-reinforced-polymer sheets

摘要

>This paper investigates the behavior of full-scale prestressed concrete girders strengthened in shear with externally bonded carbon-fiber-reinforced polymer (CFRP) sheets. The study is aimed at identifying the failure modes and effects on ultimate bearing capacity associated with the application of CFRP laminates as externally bonded shear reinforcement for prestressed concrete I-girders. A total of 16 full-scale prestressed concrete girder tests are reported. Test parameters include the cross-sectional shape, effects of preexisting damage, CFRP strengthening scheme, different anchorage systems, and transverse steel reinforcement ratio. The test results show that the failure modes are complex and can vary considerably with respect to the test parameters. The test results also show that the application of externally bonded CFRP reinforcement for shear may not yield an increase in the load-carrying capacity of a girder compared with a reference member that is not strengthened with CFRP.>References>1. Belarbi, A., S.-W. Bae, and A. Brancaccio. 2012. target="_blank" title="a€?Behavior of Full-Scale RC T-Beams Strengthened in Shear with Externally Bonded FRP Sheets.a€?" href="http://dx.doi.org/10.1016/j.conbuildmat.2010.11.102 ">a€?Behavior of Full-Scale RC T-Beams Strengthened in Shear with Externally Bonded FRP Sheets.a€? Construction and Building Materials 32 (July):  27-40. >2. NCHRP (National Cooperative Highway Research Program). 2011. Design of FRP Systems for Strengthening Concrete Girders in Shear. NCHRP report 678. Washington, DC: NCHRP. >3. Hag-Elsafi, O., J. Kunin, S. Alampalli, and T. Conway. 2001. Strengthening of Route 378 Bridge over Wynantskill Creek in New York Using FRP Laminates. Special report 135. Albany, NY: New  York State Department  of Transportation.>4. T?¤ljsten, B., A. Hejll, and G. James. 2007. target="_blank" title="a€?Carbon Fiber-Reinforced Polymer Strengthening and Monitoring of Gr??ndals Bridge in Sweden.a€?" href="http://dx.doi.org/10.1061/(asce)1090-0268(2007)11:2(227) ">a€?Carbon Fiber-Reinforced Polymer Strengthening and Monitoring of Gr??ndals Bridge in Sweden.a€? Journal of Composites for Construction 11 (2): 227-235. >5. Missouri Department of Transportation (MoDOT). 2005. MoDOT LRFD Bridge Design Guidelines. Jefferson City, MO: MoDOT. >6. ACI (American Concrete Institute) Committee 318. 2008. Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary (ACI 318R-08). Farmington Hills, MI: ACI. >7.  AASHTO (American Association of State Highway and Transportation Officials). 2008. AASHTO LRFD Bridge Design Specifications. 4th ed. Washington, DC: AASHTO. >8. Collins, M. P., and Mitchell, D. 1990. Prestressed Concrete Structures. Englewood Cliffs, NJ: Prentice Hall. >9. Al-Sulaimani, G. J., A. Shariff, I. A. Basanbul, M. H. Baluch, and B. N. Ghaleb. 1994. target="_blank" title="a€?Shear Repair of  Reinforced Concrete by Fiber Glass Plate Bonding.a€?" href=" http://dx.doi.org/10.14359/4153 ">a€?Shear Repair of  Reinforced Concrete by Fiber Glass Plate Bonding.a€?ACI Structural Journal 91 (4): 458-464. >10. Chajes, M. J., T. F. Jansuska, D. R. Mertz, T. A. Thomson, and W. W. Finch. 1995. target="_blank" title="a€?Shear Strength of RC Beams Using Externally Applied Composite Fabrics.a€?" href="http://dx.doi.org/10.14359/1130 ">a€?Shear Strength of RC Beams Using Externally Applied Composite Fabrics.a€? ACI Structural Journal 92 (3):  295-303. >11. Triantafillou, T. C. 1998. target="_blank" title="a€?Shear Strengthening of Reinforced Concrete Beams Using Epoxy-Bonded FRP Composites.a€?" href="http://dx.doi.org/10.14359/531 ">a€?Shear Strengthening of Reinforced Concrete Beams Using Epoxy-Bonded FRP Composites.a€? ACI Structural Journal 95 (2): 107-115. >12. Khalifa, A., W. Gold, A. Nanni, and M. I. Abdel Aziz. 1998. target="_