Seismic Behavior of Steel-Fiber-Reinforced High-Strength Concrete Shear Wall with CFST Columns: Experimental Investigation

Ke Shi,Ru Xue,Peibo You,Tao Zhang,Pengfei Li,Mengyue Zhang,Baoyu Cui

doi:10.3390/fib9110075

Abstract

To improve the seismic behavior of shear walls, a new composite shear wall composed of a steel-fiber-reinforced high-strength concrete (SFRHC) web and two square concrete-filled steel tube (CFST) columns, namely a steel-fiber-reinforced concrete shear wall with CFST columns, is proposed in this paper. Therefore, the main purpose of this paper is to present an experimental investigation of the seismic behavior of the SFRHC shear wall with CFST columns. Pseudo-static tests were carried out on seven composite shear walls, and the seismic performance of the shear walls was studied and quantified in terms of the aspects of energy consumption, ductility and stiffness degradation. Furthermore, the experimental results indicated that adding steel fiber can effectively restrain the crack propagation of composite shear walls and further help to improve the ductility and energy dissipation capacity of composite shear walls and delay the degradation of their lateral stiffness and force. Moreover, the seismic behavior of the SFRHC shear wall with CFST columns was obviously superior to that of the conventionally reinforced shear wall, in terms of load-bearing capacity, ductility, stiffness and energy dissipation capacity, because of the confinement effect of the CFST columns on the web. Finally, the preliminary study demonstrated that the composite shear wall has good potential to be used in regions with high seismic risk.

Highlights

Reinforced concrete shear walls are the key vertical bearing and lateral force-resisting component in high-rise buildings, widely used in earthquake-prone areas [1,2,3,4]
Point), inclined cracks of nearly 45◦ developing obliquely downward in the wall webs were observed; in addition, the paint for concrete-filled steel tube (CFST)-series specimens was peeling at the column feet of the steel tubes on both sides, but to different extents; (2) as the force increased to the maximum value (P point), the distribution pattern of cracks remained unchanged, and the width and number of cracks appreciably increased compared with the yield point
Y; concrete spalling at the column-foot-restrained edge of specimen RHC-0 was serious; obvious outward bulges of the steel tubes on both sides of CFST-series specimens were observed; at the same time, there was concrete spalling in the wall webs in the middle of the CFST-1 and CFST-2 specimens; (3) when the force was reduced to 85% of the peak value, the specimen reached the ultimate state, and the bearing capacity of the specimen decreased obviously; the concrete at the column-foot-restrained edge of the RHC-0 specimen was seriously peeled off; the buckling degree of the steel tubes on both sides of the CFST-series specimens gradually increased until torn, and the concrete at the foot of the column peeled off

Summary

Introduction

Reinforced concrete shear walls are the key vertical bearing and lateral force-resisting component in high-rise buildings, widely used in earthquake-prone areas [1,2,3,4]. The research on earthquake damage shows that the main reason for the serious damage or collapse of shear walls lies in their poor ductility and energy dissipation capacity [5,6]. In the current design code, the axial compression ratio of shear walls should be strictly limited to meet the ductility requirements and avoid brittle failure. The wall is often very thick, which reduces the usable area of the building and increases the self-weight of the structure. Dense reinforcement increases the cost and affects the construction quality [8,9]

Objectives

Results

Conclusion