Influence of reinforcement on the performance of non-seismically detailed RC beam-column joints

Beam-column connections play an important role in the seismic behavior of reinforced concrete structures. Among various factors that can affect the performance of beam-column joints, reinforcement detailing has attracted researchers' attention because of its undeniable impact on the behavior of RC joints and structures under seismic loads. In this study, the influence of reinforcement detailing (including beam longitudinal reinforcement, beam transverse reinforcement, the angle of beam stirrups and column longitudinal reinforcement) on the displacement ductility and curvature ductility is numerically investigated. To achieve the study's objective, 25 RC beam-column joint models were developed in non-linear Finite Element software; three of them were verified by a similar experimental study conducted by Li et al. The reinforcement detailing was then changed to evaluate response of the joints. Results show that by increasing the longitudinal reinforcement of beam or decreasing the size of beam stirrup, both displacement ductility and curvature ductility decrease. Another notable conclusion is that decreasing the angle of beam stirrup or increasing the longitudinal reinforcement of a column can lead to an increase in curvature ductility and displacement ductility.