Effects of fiber strength on fracture characteristics of normal and high strength concrete

The effects of steel fiber strength on the mechanical properties of steel fiber reinforced concretes, such as compressive strength, modulus of elasticity, splitting tensile strength, flexural strength, fracture energy and characteristics length have been investigated within the scope of this study. Steel fibers with two different tensile strength of 1100 and 2000 MPa, and two different volume fractions of 20 and 60 kg/m(3) were used in the production of normal and high strength concretes. Test results showed that the improvement of mechanical properties and fracture behavior by incorporation of high strength fibers is more significant in case of high strength concrete compared to normal strength concrete. This superior performance can be attributed to the lesser number of broken fibers and increased debonding process with increase of fiber strength.