FLEXURAL BEHAVIOR OF HIGH-STRENGTH FIBER-REINFORCED CONCRETE BEAMS

The effect of inclusion of steel fibers on the flexural behavior of hi gh-strength concrete beams is investigated. Eight high-strength concre te beams with different fiber contents and shear span-depth ratios wer e tested to study the influence of fiber addition on ultimate load, cr ack propagation, flexural rigidity. and ductility. The concrete matrix compressive strength was about 88 MPa (12,800 psi). The addition of s teel fibers enhanced the strength and increased the ductility and flex ural stiffness of the tested beams A semi-empirical equation is propos ed to estimate the effective moment of inertia of simply supported hig h strength fiber reinforced concrete beams. The estimated deflections using this equation agree well with the experimental values. At ultima te conditions, the length of the plastic hinge developed was found to be proportional to the fiber content.