Experimental study on simplified SRC beam-column joints in construction technology

The purpose of this paper is to propose a new type of SRC beam-column joints and to examine the structural performance of the proposed joints, which would simplify the construction procedure of steel fabrication, welding works, concrete casting and joint strengthening In the proposed beam-column joints, the steel element of column would form continuously built-in crossing of H-sections (+), with adjacent flanges of column being connected by horizontal stiffeners in a joint at the level of the beam flanges. In addition simplified lateral reinforcement (x) is adopted in a joint to confine the longitudinal reinforcing bars in columns. Seven SRC beam-and column subassemblage specimens, having parameters such as (a) stiffener's dimension, (b) thickness of column web, (c) type of joint reinforcing, (d) beam flange dimension, and (e) the amount of longitudinal reinforcing bars in beams, were prepared and tested by incremental lateral loading reversals at both ends of the beams (with constant axial load being applied to columns). The followings can be concluded from this study: (1) SRC subassemblages with the proposed beam-column joints show adequate seismic performances; (2) The yield and ultimate strength capacities of the beam-to-column connections can be estimated by analysis based on the yield line theory; (3) The skeleton curves and the ultimate shear capacities of the beam-column joint panel are predicted with a fair degree of accuracy by considering simple stress transfer mechanism.