University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 54 117 2025 02 19 Analytical modeling of rehabilitated beam-column connections with non-seismic details using joint enlargement and post-tensioned Analytical modeling of rehabilitated beam-column connections with non-seismic details using joint enlargement and post-tensioned 37 53 18189 10.22034/ceej.2024.58965.2298 FA S. Ahmad Nezami Faculty of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran Jalil Shafaei Faculty of Civil Engineering, Shahrood University of Technology, Shahrood, Iran Journal Article 2023 11 08 The inability of beam-column joints to play their key role in the seismic resistant system of the flexural frame is a subject that continues to be reported in significant damages and the threat of collapse of reinforced concrete buildings in recent earthquakes. Implementation violations and design of reinforced concrete buildings based on old regulations have caused non-seismic details to be observed in many existing connections. The operational and cost-effective technique of improvement by enlarging the connection area is one of the rare methods that, in addition to reviving the function of the connection susceptible to seismic damage, is able to enable access to high performance. In the current research, with the help of numerical modeling by the proposed method and available laboratory results, the effect of the size of the enlargement dimensions on the shear capacity of the joint area is determined. Considering the sliding effects of longitudinal beam reinforcements in the proposed method in modeling under narrow sided and cyclic loading, for non-seismic connections, 40% of stiffness and 5% of load such as yielding can lead to greater convergence with the experimental response. And this figure for reinforced joints is reduced to 35% for stiffness and 2.3% for load-like yielding. Also, intra-cycle deterioration is confirmed for unreinforced connections and non-deterioration for reinforced connections. On average, the presence of a transverse beam for non-seismic, seismic and reinforced connections causes an increase of 8.5%, 4.7% and an average of 2.15% of the force capacity of the connection, respectively The inability of beam-column joints to play their key role in the seismic resistant system of the flexural frame is a subject that continues to be reported in significant damages and the threat of collapse of reinforced concrete buildings in recent earthquakes. Implementation violations and design of reinforced concrete buildings based on old regulations have caused non-seismic details to be observed in many existing connections. The operational and cost-effective technique of improvement by enlarging the connection area is one of the rare methods that, in addition to reviving the function of the connection susceptible to seismic damage, is able to enable access to high performance. In the current research, with the help of numerical modeling by the proposed method and available laboratory results, the effect of the size of the enlargement dimensions on the shear capacity of the joint area is determined. Considering the sliding effects of longitudinal beam reinforcements in the proposed method in modeling under narrow sided and cyclic loading, for non-seismic connections, 40% of stiffness and 5% of load such as yielding can lead to greater convergence with the experimental response. And this figure for reinforced joints is reduced to 35% for stiffness and 2.3% for load-like yielding. Also, intra-cycle deterioration is confirmed for unreinforced connections and non-deterioration for reinforced connections. On average, the presence of a transverse beam for non-seismic, seismic and reinforced connections causes an increase of 8.5%, 4.7% and an average of 2.15% of the force capacity of the connection, respectively https://ceej.tabrizu.ac.ir/article_18189_00d6187636616b3c3523486bcdb4dcd1.pdf