Shear behavior of reinforced concrete beams subjected to accelerated non-uniform corrosion

In this paper, a modified accelerated corrosion method based on impressing current was adopted to generate non-uniform corrosion of stirrups in reinforced concrete (RC) beams. The shear performance of corroded RC beams was experimentally investigated, aiming to study the influence of stirrup corrosion induced by two different accelerated corrosion methods on the degradation of shear capacity of RC beams. Different corrosion degree of stirrups, corrosion of longitudinal steel bars, as well as shear span ratio were investigated. Results indicates that, the stirrups subjected to the modified accelerated corrosion method demonstrate a considerably higher circumferential and longitudinal non-uniformity, while the classic accelerated corrosion method induces a rather uniform corrosion. The non-uniformity of corrosion aggravates the propagation of both corrosion-induced and load-induced cracks, leading to the change of shear failure mode. The uniform corrosion induced by the classic accelerated corrosion method underestimates the degradation of shear capacity of RC beam, especially in the cases of corrosion degree no less than 15%. The corrosion of longitudinal steel bars mainly correlates to the decrease in the initial stiffness of RC beam, while little influence on the stiffness is observed with corroded stirrups.