Impact of Recovered and Embedded Polypropylene Fibres on the Mechanical Properties of Fibre-Reinforced Concrete

This study aims to investigate the effect of incorporating different quantities of polypropylene fibres recovered during concrete recycling or embedded in recycled aggregates on the mechanical properties of new polypropylene fibre-reinforced concrete. Both recovered fibre (at replacement ratios of 0%, 10%, 30% and 100%) and coarse recycled aggregate (0%, 100%) were used in new concrete. A polypropylene fibre content of 9 kg/m3 (1.0% by volume) was chosen for all concretes.. The compressive strength, elastic modulus and stress-strain behaviour of concrete in compression were tested. The residual tensile strength was also tested for concretes with recovered fibres and fibres embedded in recycled aggregate. The results show that mixing of recycled fibres recovered from concrete with virgin fibres is feasible without significant effect on the mechanical properties of concrete in compression.