Modelling the behaviour of steel fibre reinforced concrete using a discrete strong discontinuity approach

The use of Fibre Reinforced Concrete (FRC) is gradually wide-spreading due to the significant advantages relatively to Normal Concrete (NC). In the case of steel fibres, the quasi-brittle behaviour of plain concrete structures can be modified into an enhanced ductile behaviour as a direct result of this addition. Since the mechanical properties of both FRC and NC can be significantly different, this work aims at developing a finite element formulation to specifically address the simulation of the behaviour of FRC members up to failure. For this purpose, the Conforming Generalised Strong Discontinuity Approach (CGSDA) is adopted with steel fibres explicitly introduced in the finite element mesh. The resulting formulation has the following main characteristics: (i) variational consistency; (ii) fibre elements automatically considered regardless of the presence of cracks; and (iii) no additional degrees of freedom are required. The proposed formulation is validated using experimental results from tests conducted with different dosages of steel fibres.