The research concentrates on the composite formed by mixing of concrete mass with steel fibres, SFRC. An important property of SFRC is the ability to control crack opening, which is due to the bond between steel fibres and concrete. The fibres can retard cracks growth since they are acting as barriers on a crack path. The research proposed comprise the experimental investigation of bond properties utilising X-ray micro-tomography method. The experimental findings will serve for the calibration and validation of numerical methods used in the study. Two numerical models are considered: three-phase model of concrete involving cement paste, aggregate and adhesion layer, and discrete element model. During the study the three-phase model of concrete will be improved by adding steel fibres and simulating different adhesion properties and fibre orientations. The existing discrete element model code is expected to be improved by employing cohesive forces obtained during experimental testing.