Executive Summary : | The reinforced concrete (RC) beam-column joint is a critical component of a concrete structure, and its performance can be significantly reduced during a fire due to elevated temperatures. Current codes provide guidelines for the design of new structures against fire but do not offer guidance for post-fire performance of RC structures affected by fire. This study proposes two types of strengthening schemes: hybrid FRP strengthening technique and stiffened steel plate. Fibre-reinforced polymers (FRP) can enhance the performance of RC structural members under various loading conditions. However, only a limited number of studies have used the combination of these two FRP systems to enhance the performance of fire-affected structural members. This study aims to understand the effectiveness of the hybrid FRP retrofitting technique on emergency repair of severely damaged RC beam-column joints under combined fire and axial compression loads. The research uses the strong column and weak beam concept to design RC joints, considering parameters such as fire duration, non-ductile and ductile detailing, and un-strengthened, hybrid FRP strengthened beam-column joint and stiffened steel plate. The damaged joint will be subjected to fire loads followed by simulated lateral seismic loads. The damaged joint will be strengthened with two techniques and tested for performance evaluation. Based on experimental results and numerical parametric studies, a practical yet accurate method for post-fire assessment strategies of the RC beam-column joint will be developed. |