MECHANICAL PROPERTIES OF HIGH STRENGTH STEEL FIBER REINFORCED CONCRETE

Besides the fact that all engineering properties of concrete can be improved by adding steel fibers, the addition of fibers provides a better behaviour of the material once the matrix has cracked, by bridging across the cracks and providing post-crack ductility. This paper investigates the compressive and splitting tensile strength, modulus of elasticity and energy absobtion of high strength steel fiber reinforced concrete. Compressive strength of the high strength concrete without fibers addition, determined on 150 mm cubes, at 28 days was 102 MPa. The steel fibers were added at the volume fractions of 0.6% and 0.8%. As was expected, the compressive strength of fiber reinforced high strength concrete reached the maximum at 0.8% volume fraction, with a 21 % improvement over the HSC without fibers. The splitting tensile strength improved by increasing the fiber addition. Changing the volume fraction from 0.6% to 0.8% didn't have any effect on the value of the modulus of elasticity. Energy absorbtion of the fiber-reinforced concrete improved with increasing the volume fraction, achieving a 97.8% improvement, at 0.8% volume fraction.