Structural Testing of Dual-Core Self-Centering Braces with FRP Bars and FRP Wide-Flange Beams

摘要

This paper presents experimental performances of Fiber Reinforced Polymer (FRP)rnbars and FRP wide-flange beams used in civil engineering structures. First, the FRPrnbars made of E-glass fibers and T-700 carbon fibers were used in a newly-developedrnsteel dual-core self-centering brace (SCB) for seismic resistance. Three 5.35 m-longrnsteel dual-core SCBs which used FRP bars as tensioning elements and friction devicesrnas energy dissipation were cyclically loaded to evaluate their seismic performances.rnThe axial deformation capacity of the new brace doubled with respect to the singlecorernSCB by serial deformations of two sets of parallel FRP tensioning elements. Allrndual-core SCBs exhibited excellent performance up to a target drift of 2% and thenrnsuccessfully experienced 15 low-cycle fatigue tests at a fixed drift of 1.5%. All dualcorernSCBs were cyclically loaded again, and two SCBs achieved a drift of 2.5% with arnmaximum axial load of 1300 kN. The FRP bars suddenly fractured near the anchoragernwhen the brace was over loaded beyond the design target, leading to sudden loss of thernself-centering capacity of the brace. Second, the connection between FRP wide-flangernbeams was studied. Thirty coupon-type connection specimens, which used two or fourrnhigh-strength blots to connect a FRP plate and steel splice plates for force transfer,rnwere axially loaded to determine their ultimate tensile capacities and develop a designrnguide for the FRP beam connection in Taiwan. Six 6.5 m-long FRP beamsrn(H410×200×18×20 mm), three of which were connected by high-strength bolts andrnsteel splice plates, were subjected to a four-point bending test up to failure. These FRPrnbeams exhibited similar flexural capacities without connection failure, but therncompression failure or delamination occurred when the top flange compressive strainrnreached 0.3 to 0.4%. These works showed the potential use of applying FRP bars inrnthe novel steel dual-core SCB for seismic resistance and FRP beams in temporaryrnbridges for the purpose of rescue in Taiwan.