Effect of shear reinforcement corrosion on interface shear transfer between concretes cast at different times

Abstract This paper experimentally investigated the interface shear transfer between concretes cast at different times (that is, cold joints) after shear reinforcement corrosion. Twelve cold joint push-off specimens were cast and the impressed current accelerated corrosion test was used to obtain different values of shear reinforcement corrosion degree. Push-off tests were then conducted to study the shear transfer behavior of cold joint after shear reinforcement corrosion. The push-off test results indicate that cold joints with different values of shear reinforcement corrosion degree exhibit distinct failure modes. As the corrosion degree increases, the interface failure mode gradually changes from shearing off of the shear reinforcements to spalling of the concrete cover. The shear capacity and failure load of interface reduce and the interface deformation (relative slip and crack width) at the shear capacity increases with the increase of corrosion degree. The stiffness of shear load-interface deformation response is reduced and a more ductile shear transfer behavior is observed after shear reinforcement corrosion. The shear mechanism analysis results reveal that the reduction of interface shear capacity is mainly due to the decrease of interface adhesion or cohesion caused by the shear reinforcement corrosion, and the decrease of interface failure load attributes to the change of the interface failure mode. Based on the statistical analysis of the test data in this paper, the equations for predicting the shear strength and failure strength of cold joint after shear reinforcement corrosion are proposed.