Effects of corrosion on shear behaviour of discontinuous perfobond rib shear connectors

To study the effect of steel corrosion on the shear resistance of new shear connectors, push-out tests were carried out on three groups of six discontinuous perfobond rib shear connectors with different corrosion ratios. After testing, the displacement, strain distribution, crack development and relative slip between concrete and steel were assessed. Based on the experimental work, the effects of corrosion of perfobond ribs and transverse rebars on the shear resistance of the connectors were studied using finite-element models. The results showed that when the corrosion ratio was low, the corrosion of the perfobond rib increased the cohesion between the steel and the concrete, thereby improving the initial stiffness and ultimate bearing capacity (UBC) of the structure. With an increase in the corrosion ratio, expansion cracks on the joint surface led to bonding failure between the steel and concrete and the shear resistance of the structure was greatly reduced. When the corrosion ratio of the transverse rebars was 10%, the UBC of the connection decreased by only 5% and the initial stiffness hardly changed.