Fracture mechanics of reactive powder concrete: material modelling and experimental investigations

Reactive powder concrete (RPC) is made of very a fine matrix with short steel fibres. To optimise the mechanical behaviour, the influence of the orientation of fibres due to the process of casting must be studied. By considering a locally oriented mass of fibres as an inclusion embedded in a homogeneous medium of concrete, the Eshelbyʹs inclusion model provides a description of the micro-structural strain concentration and permits to develop a model for crack initiation based on equivalent strain criterion. By using the micro-plane model coupled with damage theory we can reproduce the crack propagation in relation with the orientation of the fibres. Specimens of RPC with a given orientation of fibres, tested under uniaxial tension, confirm such a role played by a locally anisotropic elastic behaviour on crack initiation, and on the bridging action during crack propagation.