Seismic behavior of steel fiber-reinforced high-strength concrete mid-rise shear walls with high-strength steel rebar

Abstract

To investigate the seismic behavior of shear walls with high-strength materials, cyclical quasi-static tests on five half-scale shear walls with an aspect ratio of 1.5 were carried out, including four conventional reinforced concrete walls and one composite wall. The steel fiber-reinforced concrete shear wall with HRB 600 MPa reinforcement located completely in the boundary element and in the wall web was taken as the reference specimen. The presence of steel fibers, the strength of wall web rebar, and the presence of high-strength reinforcement diagonal bracing (X configuration) were selected as major test parameters for the other three conventional walls. The results reveal that the high-strength concrete (HSC) shear wall with high-strength steel rebar (HSSR) showed stable hysteresis performance, and all specimens had acceptable crack widths and residual deformations before a lateral drift of 1%, except for the nonfiber-reinforced concrete specimen. The addition of steel fibers can reduce the crack width, limit the shear crack development, and increase the flexibility deformation, thus improving the deformation capacity of the specimens. Using HRB 600 MPa reinforcement instead of HRB 400 MPa reinforcement as wall web rebar can significantly reduce the residual deformation. The specimen with high-strength reinforcement diagonal bracing in the wall web and the composite shear wall with a built-in steel truss not only had desirable repairability after a large earthquake but also showed much higher energy consumption capacity under a strong earthquake. Finally, based on the experimental and theoretical analysis, a simple method for calculating the lateral strength was established, and the predicted results showed good agreement with the test data.