Flexural and shear behavior of geo-grid confined RC beams with steel fiber reinforced concrete

• This study examines the feasibility of geo-grid confinement in RC beams.
• Geo-grid confined RC beams with SFRC under flexure and shear is investigated.
• Grid confinement enhances the stiffness degradation and energy dissipation property.
• Composite action of grid and SFRC alters the failure mode.
• Flexural and shear behavior authenticates the feasibility of geo-grid in RC beams.

An experimental study is carried out to examine the feasibility of geo-grid as additional shear reinforcement in RC beam specimens. The use of geo-grid as confinement in the RC beams is easier and less laborious and may also be an effective solution along with the conventional way of confinement. Basically, geo-grid is not as rigid as conventional steel reinforcement and its reliability of anchorage with flexure reinforcement in the form of hoop under severe earthquake may advocate the use of another alternative path not only for resisting the flexure and shear but also to make more effective confinement in the form randomly distributed steel fiber in reinforced concrete (SFRC). Twelve sets of beam specimens are divided into three types with different configuration based on ratio of longitudinal and transverse reinforcement, strength of geo-grid and volume of steel fiber. These geo-grid beam specimens are tested under single point static loading to obtain the comparative load–deflection behavior. The experimental test shows a significant improvement in the strength and post-yield behavior of beam specimens depending on % of steel fiber reinforced concrete and the use of partial geo-grid confinement. The test results indicate that the proper application of geo-grid with steel fiber reinforced concrete not only helps to achieve the ductile behavior but also alters the brittle mode of failure.