Bond stress slip response of bars embedded in hybrid fibre reinforced high performance concrete

Pullout tests were carried out to study the effect of steel-polypropylene hybrid fibres on the bond strength and bond stress–slip response of deformed reinforcement bars embedded in high performance concrete. A total of 96 specimens were cast and tested in the present investigation. The main variables considered were the volume fraction of crimped steel fibres, volume fraction of polypropylene fibres and the diameter of reinforcement bars. The combination of 1% volume fraction of steel fibres and 0.10% volume fraction of polypropylene fibres gave better performance with respect to bond strength than the other combinations considered in this study.