RESISTANCE FACTORS FOR DUCTILE FRP REINFORCING BARS

摘要

The use of steel reinforcement in concrete structural components often leads to costlyrnmaintenance requirements as a result of corrosion, and has led to the use of fiber reinforcedrnpolymer (FRP) bars for some applications. A major disadvantage of typical FRP bars is thernresulting lack of ductility. Recently, ductile FRP bars have been developed for use in concreternflexural members with resulting ductility indices similar to sections reinforced with steel.rnHowever, appropriate design strength reduction factors for concrete members using ductile FRPrnbars have not been developed. This paper addresses this concern and presents a reliability-basedrnanalysis in which resistance factors for concrete flexural members reinforced with ductile FRPrnbars are estimated. Load and resistance random variables are quantified and a reliability modelrnis developed for different ductile bar configurations for reinforced concrete bridge decks. Thernresistance factors are developed such that concrete bridge decks reinforced with ductile FRP barsrnmeet the target reliability index for AASHTO LRFD. The tension-controlled factors ranged fromrn0.61 to 0.64, resulting in an increase in allowable design strength over that obtained from currentrnrequirements for tension-controlled concrete decks reinforced with non-ductile bars.