Hysteretic behavior of high-performance frame-shear wall composite structure with high-strength steel bars

Abstract

Three 2-story frame-shear wall structures that integrated the advantages of composite structure and high-performance materials were designed and tested under cyclic lateral loading to develop a high-performance structure with satisfactory seismic behavior and reparability. HRB 600 MPa steel bars (i.e., hot rolled ribbed rebar with nominal yield strength of 600 MPa) and 1400 MPa ultra-high strength (UHS) steel bars were used for vertical component reinforcement, and different reinforcement configurations were taken as the design parameters. The results showed that the proposed structure can be repaired at a large drift of 2% and ensure sufficient collapse resistance capacity as well. The structure only reinforced with HRB 600 MPa longitudinal bars in vertical components showed better energy consumption capacity but serious concrete damage. Replacing all HRB 600 MPa longitudinal bars with an equal strength of UHS longitudinal bars have a more pronounced role in avoiding the deformation and damage concentration in the lower floor and controlling the growth rate of residual drift than partially replaced hybrid reinforced structures. The UHS reinforcement concealed bracing can effectively decrease the shear strength degradation, control the damage of shear wall, and improve the reparability of the structure. According to the failure mechanism, an ideal load-deformation response to reflect the damage state was proposed.