FLEXURAL BEHAVIOR AND DESIGN OF RC MEMBERS USING FRP REINFORCEMENT

Flexural design for concrete members reinforced with fiber-reinforced- plastic (FRP) composites may be conducted using both the ultimate-stre ngth method and the working-stress method. Since FRP reinforcement doe s not yield, there should be the explicit provision that failure be co ntrolled by concrete crushing as opposed to reinforcement rupture. Def lection control may become as important as flexural strength for the d esign of FRP-reinforced concrete structures. The paper contends that, at this stage of development, the working-stress method is better suit ed to FRP-reinforced concrete. The primary reasons are that the predic ted ultimate moment capacity represents a highly variable state only a ttainable at a high level of deformation and crack opening and that it depends strictly on concrete ultimate strain. FRP reinforcement is be tter suited to pre- and posttensioned-type concrete members; however, it cannot be ruled out that FRP should become the reinforcement of cho ice in special nonprestressed applications where durability or magneti c permeability are the controlling parameters.