Behaviour of non-seismic detailed reinforced-concrete beam-column connections.

In many developing countries, existing reinforced-concrete buildings were originally designed to resist mainly gravity loads, and are vulnerable to earthquake loads. In particular, exterior beam-column connections might show brittle structural behaviour due to the discontinuity of the beams, weak confinement of concrete inside the connections, and unreliable load-transferring mechanism dependent on concrete tensile strength. The aim of this study is to investigate experimentally the seismic performance of six half-scale test specimens simulating exterior beam-column connections in existing reinforced-concrete buildings with non-seismic reinforcement details. The main test parameters of this study include the longitudinal reinforcement ratio of concrete beams and configurations of steel reinforcement inside the connections. The test results show that the structural performances of the beam-column connections (e.g. failure mode, load-drift ratio relationship, shear deformation and energy dissipation of the connections) are mainly affected by the amount of longitudinal reinforcing bars in beams. In addition, the existence of transverse hoops inside the connections slightly increases the lateral load-carrying capacity and reduces the shear deformation in the connections. [ABSTRACT FROM AUTHOR]