Experimental investigation into the failure process of exterior beam-column joints with high-strength reinforcements

Several structural systems resist earthquake-induced forces such as shear walls, moment frames, and dual systems (moment frames with shear walls). Although there are many studies on performance of the lateral resisting systems [1-5], but these systems have some usage limitations such as height of structures, etc. [6]. For instance, special moment frames along with shear walls are earthquake-resisting systems that high-strength reinforcement (HSR)‒steel reinforcements with the yield strengths greater than 500 MPa‒ application is restricted in them due to possible repercussions of HSR application [7,8]. There are considerable challenges against the HSR application such as increasing the crack width, the brittle failure, decreasing the ductility and energy dissipation. On the other hand, HSR application has several benefits, such as diminishing the labor and material costs, reducing construction time and facilitating the construction procedure [6]. Damage indices can be calculated based on different parameters such as strain, stress, displacement, dissipated energies, stiffness, and ductility. Several researchers have proposed Damage indices (DI) for different types of structures during recent years. These indices have been modified and calibrated by passing the time.