Dynamic Behavior of Carbon Fiber-Reinforced Polymer- Strengthened Reinforced Concrete Beams without Stirrups under Impact Loading

摘要

The paper experimentally investigates the effects of carbon fiber-reinforced polymer (CFRP) strengthening arrangements on the failure mechanisms of CFRP-strengthened reinforced concrete (RC) beams without stirrups under impact loading, as well as the fiber-reinforced polymer (FRP) contribution to shear strength. Five beams were tested under static loads and 10 beams under impact loads. The failure modes and the shear mechanism of CFRP-strengthened RC beams under impact loading were obtained. The failure process can be divided into two stages: the shear failure of the local part of the beams adjacent to the midspan section under impact loading: and the subsequent shear failure of the near-support section under reaction force. The test results showed that the arrangement and amount of CFRP as well as impact energy played an important role in the beam dynamic behavior. The CFRP contribution to shear strength at the first stage was discussed and verified by the experimental shear strength considering the strain rate and stress wave propagation effects. A dynamic failure criterion of RC beams was eventually proposed to assess the failure of FRP-strengthened RC beams under impact loading.