Flexural behavior of concrete T-beams reinforced with glass fiber reinforced plastic (GFRP) bars

Concrete slabs are integrally cast with girders/stringers (stiffening system) as floor slabs, bridge decks, retaining structures and others. A portion of slab bends in unison with the stiffening system; thus resulting in Tee beam action. It is, therefore, necessary to study the pre- and post-cracking behavior of FRP reinforced concrete T-beams including shear-lag phenomenon in flanges, develop ultimate bending capacity equations, and compare them with the existing ACI design equations. Eight concrete Tee beams with different flange widths, effective spans and reinforcement configurations were tested under four-point bending. Strains on FRP bars, concrete strains across the flange, crackwidths and mid-span deflections were measured to evaluate pre- and post-cracking stiffness of the beams. Failure mode types and deformability factors are discussed in this paper.