Seismic tests on reinforced concrete beam-column joint sub-assemblages subject to lateral and long-term vertical load

The testing of the one-third scale four plane reinforced concrete interior beam-column joint sub-assemblages are presented in this paper. The specimens are designed to allow for a beam yielding mechanism by limiting the joint shear and are statically cyclic loaded in both directions with increasing amplitude. Variables of the test are chosen as with or without a constant downward force simulating gravity load on the beams and the column-to-beam strength ratio. Severe beam-column joint damage is observed in some specimens. In specimens with column-to-beam strength ratio of 1.18, with simulated gravity load on the beams, yielding of the longitudinal reinforcement in top column occurred at an early stage and only the deflection of top columns progressed. This trend was not observed in other specimens without simulating gravity load or specimens with column-to-beam strength ratio of 2.22.