Behaviour of Hybrid Steel and FRP-Reinforced Concrete—ECC Composite Columns under Reversed Cyclic Loading

Abstract

Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear–elastic property of FRP reinforcement. Hybrid steel—FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel—FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel—FRP-reinforced concrete—engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel—FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially.

Compressive Behavior of Composite Concrete Columns with Encased FRP Confined Concrete Cores

“…Currently, in regard to modern engineering structures, carrying capacity and deformation properties are in great demand [1]. In the past two decades, fiber reinforced polymer (FRP) composites have been widely applied in civil engineering construction, because of their several advantages, such as higher corrosion resistance, higher strength to weight ratio, and superior durability in aggressive environments [2].…”

Axial Compressive Performance of a Composite Concrete-Filled GFRP Tube Square Column

“…Fiber-reinforced polymer (FRP) tubes, which are characterized by light weight, high strength, corrosion resistance, easy processing, and fatigue resistance, were first applied to military facilities in the US, and then to the construction field by British engineers [1,2]. An FRP-confined concrete column is a composite component formed by wrapping FRP on the outside of the concrete column.…”

Seismic Behavior of RC Bridge Piers Locally Replaced with SFRC‐FA Subjected to Torsion Combined with Axial Compression

“…FRC and ECC are efficient cement-based composites that can compensate for the drawbacks of quasibrittleness of conventional concrete and has better structural performance than conventional concrete [23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Zhang et al [24][25][26] conducted the seismic performance tests of steel fiberreinforced concrete (SFRC) locally reinforced hollow piers at the potential plastic hinges, which showed that the application of SFRC can improve the ductility and bending performance of the piers.…”

“…e proposed model estimated the shear behavior of the SFRC members well. e test results by Li et al [31][32][33][34][35] indicated that the use of ECC materials in the connection plastic region as a replacement of conventional concrete and partial replacement of transverse reinforcement can significantly enhance the joint shear resistance, energy absorption capacity, and cracking response. erefore, it has been shown that FRCs materials represent a feasible alternative for use in earthquake-resistant structures [33].…”