Investigation of flexural properties of high-performance cementitious materials reinforced with Dramix steel fibers

Concrete has high compressive strength but has very low tensile strength, and relatively high fragility has made the tensile strength of concrete impossible in design regulations. The use of steel fibers in concrete matrices reduces the brittleness and fragility of concrete. Improving the mechanical properties makes the reinforced concrete matrix with metal fiber a suitable material for structural applications. In the present study, the mechanical properties of cement-based reinforced composites with different fiber volume percentages (1% and 2%) have been investigated. The cement-based matrix has a compressive strength of 64 MPa and fibers used by the Dramix family (3D, 4D, and 5D). In this study, to evaluate the flexural strength, a 4-point flexural test was performed on flexural elements reinforced with different percentages of steel fibers. Bending parameters such as displacement force diagram, crack state, energy absorption, and flexural stress are evaluated and compared. The results show that in some samples, the stiffening behavior occurs before the crack and rupture concentration, and then the strain-softening behavior. The occurrence of hardening behavior improves the mechanical properties of the material. In this case, the rupture of the specimens occurs through the creation of multiple cracks.