Evolution characteristics of secondary tensile mechanical properties of corroded rebars

The effects and causes of different factors on the secondary tensile mechanical properties of corroded rebars (reinforcing bar) after yielding were investigated through experimental and simulation analyses to evaluate the secondary resistance performance of corroded rebar concrete members after stress and yielding. Different specimens were designed, and the rust depth, unloading level, and aging time of the rebars were used as influence variables in loading and unloading tests. The influence of each variable on the secondary tensile mechanical properties of corroded rebars after tensile yielding was studied, and reliability was verified by simulation analysis. The results showed that (a) when corroded rebars were in monotonic or secondary tension, the plastic deformation performance gradually decreased with the increase in corrosion depth, the engineering tensile strength decreased, and the pit section tensile strength increased; (b) the cold-draw hardening and aging properties of corroded rebars had no remarkable correlation with corrosion depth. (c) corrosion does not change the stress-strain constitutive relationship of the rebars during monotonic or secondary tension but affects the similarity of the stress-strain curve to the load-displacement (or average engineering stress-strain) curve of intact rebar.