STATIC AND FATIGUE BEHAVIOR OF CFRP-STRENGTHENED RC BRIDGE GIRDERS SUBJECTED TO VEHICLE OVERLOADING

This paper presents an experimental study into the static and fatigue behavior of three pairs of small-scaled reinforced concrete (RC) bridge girders, in order to investigate the influences of overloading on the fatigue strengthening effects of externally bonded carbon fiber reinforced polymer (CFRP) laminates and understand the mechanisms of fatigue damage accumulation in CFRP-strengthened RC bridge girders under vehicle overloading. Two pairs were strengthened with CFRP laminates and the remained one pair was un-strengthened as references. Two types of overloading were implemented in this test program: one was overloading both prior to and after FRP strengthening and the other was cyclic overloading only after FRP strengthening. At the end of the cyclic overloading all the girders were tested under monotonic loading until failure. Through the evaluation of the pre-fatigue static strength, the development of deflection and cracks during the fatigue loading and the post-fatigue strength of both un-strengthened and CFRP-strengthened RC girders, the effects of the above two different types of overloading on their static and fatigue behaviors are extensively discussed.