Experimental and numerical investigation on the cyclic behavior of RC beam column joints with EAF slag concrete

An experimental and numerical study about exterior reinforced beam-column joints made with recycled concrete containing Electric Arc Furnace (EAF) slag aggregate, and subject to horizontal reversed cyclic loading, is shown in this paper. Three real scale joints were tested under quasi-static cyclic loading, to study the influence of EAF concrete use on the global behavior of the specimens, in terms of ultimate load, hysteresis response and dissipated energy. The joints exhibited the same failure mode, which involved the shear failure of panel joint and yielding of beam steel longitudinal bars. Then a numerical investigation was carried out, consisting of three-dimensional non-linear finite-element (FE) models, which were validated with the experimental results. Lastly, a parametric study was carried out to understand the effects of column axial load, beam longitudinal reinforcement bar amount and column transverse reinforcement ratio. Results indicate that, in all the analyzed cases, the seismic performance of the joints made with EAF slag concrete is better than with conventional material.