Seismic performance of interior beam‐column joints constructed with hybrid polyvinyl alcohol and steel fibers reinforced cementitious composites

Abstract Beam‐column joints play a vital role in avoiding catastrophic damage to moment frames. This study presents an investigation of the seismic performance of interior beam‐column joints constructed using hybrid fibers reinforced cementitious composites (HyFRCCs), which are composed of polyvinyl alcohol (PVA) and steel (ST) fibers (PVA/ST‐HyFRCCs), conducted through experimental tests and numerical simulations. Four interior beam‐column joints, including three PVA/ST‐HyFRCCs specimens and one concrete specimen, were tested under reversed cyclic loading. The effects of axial compression ratio and stirrup ratio in the panel zone on the hysteresis response of the specimens were estimated in terms of the crack pattern, failure mode, displacement ductility, stiffness degradation, and energy dissipation. A three‐dimensional numerical model was developed to evaluate the influence of fiber dosage, length of ST fibers, and amount ratio of PVA and ST fibers. It was concluded that removing all stirrups from the panel zone is not favorable. The seismic performance of the HyFRCCs beam‐column joints was more sensitive to the fiber dosage in HyFRCCs than to the length of ST fibers and the amount ratio of PVA and ST fibers. Substituting ST with an identical amount of PVA fibers is effective in improving the ductility of HyFRCCs beam‐column joints.