Seismic behaviour of cross-shaped steel fibre reinforced concrete columns

Abstract

This paper proposes a novel cross-shaped column in which steel fibre reinforced concrete (SFRC) is integrated with a highstrength stirrup to enhance its seismic behaviour. An experimental investigation was conducted on eight cross-shaped column specimens subjected to cyclic lateral loading. All of the specimens were evaluated in terms of their cracking patterns, failure modes, hysteresis behaviour, deformation and ductility, strength and stiffness degradation, and energy dissipation performance. The effects of the stirrup strength, stirrup spacing, steel fibre content, and axial load ratio were investigated. The experimental results demonstrated that all of the specimens exhibited flexural failure. The cracked concrete of the specimens with steel fibres could be prevented from spalling. The hysteresis loops of all of the specimens were relatively full without a readily observable pinching phenomenon and the specimens possessed a satisfactory energy dissipation capacity. Compared with the normal specimens, the specimens with high-strength stirrups, close stirrup spacing, and steel fibre exhibited a higher energy dissipation capacity, lateral bearing capacity, displacement ductility, and initial stiffness. However, the ductility rapidly decreased as the axial load ratio increased. Additionally, neither the incorporation of steel fibre nor the reduction of the stirrup spacing or the axial load ratio substantially mitigated the stiffness degradation. Based on the test results, calculation models were proposed for calculating the seismic bending moment capacities of the specimens. The calculated values were in accordance with the test results.

Mechanical Properties and Microstructure of Rice Husk Ash–Rubber–Fiber Concrete under Hygrothermal Environment

“…Due to the shortcomings of self-weight and low tensile strength of concrete, many scholars have made up for these shortcomings by adding various fibers [20][21][22]. Jianqiang Wei et al [23] found that when the substitution rate of rice husk ash was 30%, the alkaline degradation and mineralization of sisal fiber in cement matrix were alleviated most effectively, which ensured that sisal fiber-made green natural fiber-reinforced cement composites have better tensile properties and durability.…”

Influence of Fiber Shape and Volume Content on the Performance of Reactive Powder Concrete (RPC)

“…It was reported that the properties were greatly influenced by the aspect ratio [22,23], tensile strength [23], shape [24][25][26][27], and volume content [28][29][30] of steel fibers, and the shape and volume content are the two most frequently studied factors. Generally, the strength of RPC or UHPC improves gradually with the increase of steel fiber content [31][32][33][34][35][36][37][38].…”