Behavior of Aramid Fiber-Reinforced Polymer Reinforced High Strength Concrete Beams under Bending

Flexural test results of ten high strength concrete beams reinforced with aramid fiber-reinforced polymer (AFRP) bars together with a steel-reinforced beam that served as a reference are presented and discussed. All beams were tested under third-point loading. Test results have shown that a concrete beam, when reinforced with AFRP bars, becomes more flexible in the postcracking range than an equivalent steel-reinforced beam, demonstrates wider and predominantly vertical cracks even in the shear span, and may fail in an unusual flexure-shear mode. Major critical issues concerning flexural designs of AFRP-reinforced beams have been discussed in the perspective of code provisions, and suitable recommendations are made for practical design. A method has been suggested to provide a meaningful quantification of ductility for FRP-reinforced beams. Also the need for reducing the maximum spacing of stirrups from that specified in the current code provisions for sections subjected to large shear combined with significant bending moment has been identified and recommendations are made.