Seismic Performance of Ultra-high Performance Concrete-Filled Steel Tube Composite Columns Reinforced with Steel-FRP Composite Bars
GE Wenjie
ZHANG Zhiwen
ASHOUR Ashraf
CAO Dafu
LI Shengcai
Abstract：To address the rapid stiffness degradation and significant residual deformation of concrete-filled steel tube columns under seismic loading,a novel composite column,the ultra-high performance concrete-filled steel tube(UHPCFST)reinforced with steel-FRP composite bars(SFCB),was proposed.A series of cyclic loading tests was conducted to evaluate its seismic performance.The results indicate that,compared to UHPCFST columns reinforced with either steel bars or basalt fiber-reinforced composite bar,those columns reinforced with SFCB exhibit intermediate levels of load-bearing capacity,ductility,energy dissipation,and residual deformation.Both methods of increasing the SFCB reinforcement ratio and replacing conventional concrete with ultra-high porformance contrece(UHPC)in the steel tube can enhance the seismic performance of the composite column.Moreover,a high axial compression ratio benifits the load-bearing capacity,initial stiffness,and energy dissipations,but accelerates stiffness degradation and reduces ductility.When the SFCB reinforcement ratio increases from 3%to 4%,the comprehensive seismic performance of the composite column improves by 21%,while material costs rise by only 5%.Therefore,increasing the SFCB reinforcement ratio is the most cost-effective approach to enhancing the seismic performance of composite columns.
Keywords：ultra-high performance concretesteel-FRP composite barcomposite columnseismic performancepseudo-static test
Publication Date：2026-01-31
Online Publishing Date：2026-03-17(First online date of this platform, not the publication date of the document)
Pages：10( 87-96 )