Flexural Behavior of Fiber-Reinforced-Concrete Beams Reinforced with FRP Rebars

Synopsis: The main objective of this study was to develop a nonferrous hybrid reinforcement system for concrete bridge decks by using continuous fiber-reinforced-polymer (FRP) rebars and discrete randomly distributed polypropylene fibers. This hybrid system has the potential to eliminate problems related to corrosion of steel reinforcement while providing requisite strength, stiffness, and desired ductility, which are shortcomings of the FRP reinforcement system in reinforced concrete structures. The overall study plan includes (1) development of design procedures for an FRP/FRC hybrid reinforced bridge deck system; (2) laboratory studies of static and fatigue bond performances and ductility characteristics of the system; (3) accelerated durability tests of the hybrid system; and (4) static and fatigue tests on full-scale hybrid reinforced composite bridge decks. This paper presents the results relating to the flexural behavior of the polypropylene-fiber-reinforced-concrete beams reinforced with FRP rebars. Test results indicated that with the addition of fibers, the flexural behavior was improved with an increase of ductility index by approximately 40 % as compared to the plain concrete beams. Crack widths of FRP/FRC were found to be smaller than those of FRP/plain concrete system and the values predicted by the current ACI 440 equations. Furthermore, the compressive failure strains of concrete in FRP/FRC beams exceed the strain of 0.0040 mm/mm