Shear Failure of Concrete Beams Reinforced with 3-D Fiber Reinforced Plastic Grids

Results of tests of ten concrete beams reinforced with fiber-reinforced plastic grids fabricated from small pultruded profiles are presented. The beams were designed to investigate the behavior and performance of the grids when used to reinforce beams that develop significant flexural-strength cracking (a/d = 3). Different grids were designed to study the influence of the main bars, vertical bars and transverse bars (cross-rods) of the grid on the failure loads and failure modes. From the results of the testing it was concluded that pultruded grids can provide effective shear reinforcement, however, their design must account for failure of the main bars in the shear span. Overreinforced beams failed in a somewhat more ductile manner than underreinforced beams.