Recently, flattening beam cross sections is getting popular to create open living space in RC residential buildings, resulting in flat beam-column joints. However, the structural performance of T-shaped flat beam-column joints has not been clarified. Therefore, in this study, static loading tests were conducted on three T-shaped flat beam-column partial moment-resisting frame specimens to investigate the structural performance. As a result, the beam-to-column flexural strength ratio significantly affected the structural performance of the specimens, showing that the experimental lateral resistance of the specimen with the ratio of approximately 1.0 didn’t exhibit the design strength assuming yielding of member longitudinal rebar.
