Influence of slab on the seismic response of sub-standard detailed exterior reinforced concrete beam column joints

Abstract

For the seismic performance assessment of existing sub-standard detailed exterior
\nbeam-column joints, it is critical to accurately establish the hierarchy of strength
\nof each element and therefore the likely failure mechanism. However, in current
\npractice, the influence of cast-in-situ slab and transverse beams is typically
\nneglected or calculated based on equations that were derived from modern
\ndetailed beam-column joint subassembly tests. In literature, experimental studies
\nfor non-ductile beam-column joints constructed prior to the 1970s, thus before the
\nintroduction of capacity design principles, explicitly considering the influence of
\nslabs are scarce. This paper presents the experimental results of comprehensively
\ninstrumented four 2/3-scaled one-way (two-dimensional, 2D) and two-way (threedimensional,
\n3D) 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.