Rate effect on interfacial response between fibres and matrix

A study on steel fibres pulled out from a cementitious matrix at different slip rates was conducted. A measurement system, which allows one to use two independent methods to evaluate pull-out load, was developed for the Charpy pendulum. Two series of specimens, with 16 and 8 fibres, respectively, were tested. Effects of the rate of slip and of numbers of fibres on interfacial behaviour have been examined. A theoretical model to predict the slip-rate effect on fibre pull-out has been proposed based on fracture mechanics. Based on the peak fibre pull-out load of a reference specimen with a static slip-rate, the proposed model can predict peak pull-out loads and corresponding slips at faster slip-rates.