Mechanics of fibre-reinforced cementitious composites

This paper will describe a procedure for modelling the complete macroscopic response (including strain hardening and tension softening) of short fibre reinforced cementitious composites and show how their microstructural parameters influence this response. The strain hardening is essentially due to elastic bridging forces which are proportional to crack opening displacements. On the other hand, an elasto-plastic bridging law governs the initial tension softening response of the composite. To facilitate the investigation of the localisation process as an instability phenomenon perturbations in microcrack sizes are considered. The perturbations may be the result of varying aggregate sizes. The instability caused by the perturbations in the bridging force exerted by the fibres is also studied.