Influence of slab on the seismic response of sub-standard detailed exterior reinforced concrete beam column joints
For the seismic performance assessment of existing sub-standard detailed exterior beam-column joints, it is critical to accurately establish the hierarchy of strength of each element and therefore the likely failure mechanism. However, in current practice, the influence of cast-in-situ slab and transverse beams is typically neglected or calculated based on equations that were derived from modern detailed beam-column joint subassembly tests. In literature, experimental studies for non-ductile beam-column joints constructed prior to the 1970s, thus before the introduction of capacity design principles, explicitly considering the influence of slabs are scarce. This paper presents the experimental results of comprehensively instrumented four 2/3-scaled one-way (two-dimensional, 2D) and two-way (threedimensional, 3D) exterior beam-column joints with and without slabs. Tests were conducted under uni-directional and bi-directional quasi-static lateral loading with concurrent varying axial loading. Comparison in terms of global and local behavior between specimens show the influence of the floor slab and the transverse beam in the resistance mechanism of the beam-column-joint subassembly elements in different ways, depending on the type of frame and the loading protocol. Preliminary recommendations for assessment are tentatively provided as closure.