Mechanical Behavior of Reinforcement Stirrups BSt 500s at Corrosive Environment

To date, there is no widely accepted regulation on the minimum required diameter of the bending drums, which shape the stirrups of the main concrete reinforcing bars, varying between 4 and 12 times the diameter of the bent bar, and thus resulting in various plastic strains. In the present work, the influence of the degree of plastic strain on the mechanical properties of steel bar of Class BSt 500s for concrete reinforcement stirrups is investigated, under the additional implication of laboratory corrosive conditions. The increase of the degree of the plastic strain of the stirrup bar had as a result a significant decrease in the ductility properties of the steel. Moreover, it is shown that the combination of plastic strain and corrosion causes additional damages, as strain fractures were recorded lower than that defined by the current specifications for concrete reinforcement, indicating the need for a new review of the relative specifications.