Experimental study on seismic performance of steel fiber reinforced high strength concrete composite shear walls with different steel fiber volume fractions

Abstract

The concrete at the bottom corner of the reinforced concrete shear walls is easily crushed to failure under vertical and horizontal loads owing to its low tensile strength. Casting steel fiber reinforced high strength concrete (SFRHSC) in the plastic critical zone at the bottom of the shear walls is expected to improve the seismic performance of these walls for steel fibers can raise the toughness of high strength concrete (HSC). Based on the previously determined mechanical properties of SFRHSC, a type of SFRHSC composite shear wall was developed in this work. SFRHSC and HSC were cast in the lower and upper halves, respectively, and a steel profile was placed in each boundary member of the walls. Nevertheless, the influence of the steel fiber facture volume on seismic performance of the SFRHSC composite shear walls remains unclear. This paper aims to investigate the effect of the steel fiber volume fraction on the non-linear behavior of a SFRHSC composite shear wall. Four SFRHSC composite shear walls with 1/2 scale and shear span ratio of 2.25 were subjected to low cyclical quasi-static testing. Each specimen was tested under cyclically increasing lateral loads and a constant relatively high vertical load until failure. The impact of steel fiber on the seismic performance of composite elements with fiber volume fraction of 0%, 1.0%, 1.5% and 2.0% was evaluated. The results revealed the coordinated working performance of the SFRHSC composite shear wall. The deformation capacity of the SFRHSC composite specimen was higher than that of the HSC composite shear wall and the flexural deformation improved gradually, as the steel fiber prevented cracking of the cement matrix. Crack and damage process were postponed, and damage degree was reduced with increasing steel fiber volume fraction. Furthermore, the energy dissipation ability improved significantly, when a fiber volume fraction of 2.0% was employed.