Development of finite element model for embedded carbon fiber-reinforced polymer rod in reinforced concrete frame joints

The stiffness and strength of joints are the main factors in providing stability and ductility of a structure during dynamic load such as earthquake. In the high-humidity areas, the reinforcement is exposed to corrosion, which commonly occurs in the joints, due to the presence of micro-cracks in the joints, shrinkage or other concrete casting issues. Therefore, one of the main failure mechanisms of building during an earthquake is caused by damage in the joints in humid areas. This is mainly caused by corroded steel reinforcement, which reduces functionality of the frame joints in transferring the loads. This study proposes a new design for reinforced beam-column joints with embedded carbon fiber-reinforced polymer rods, which possesses extremely high strength and resistance against corrosion and high stiffness. The finite element model for embedded carbon fiber-reinforced polymer in the joints was developed in order to evaluate the performance of the proposed joints during earthquake execution. The developed program was verified through an experimental test on reinforced concrete frame subjected to vibration using dynamic actuator. The finite element program was implemented for one-story reinforced concrete frame and two-story frame building with proposed joints and seismic analysis. The results demonstrated a significant improvement in the performance of the frames reinforced with embedded carbon fiber-reinforced polymer in joints in terms of lateral load resistance capacity and failure mechanism.