ABSTRACT
This paper investigates the corrosion morphology and the degradation of mechanical behavior of corroded prestressing strand under artificial climate conditions. Nineteen specimens with different corrosion degrees were obtained by controlling chloride ion concentration, stress level and corrosion time. Results show that the corrosion loss of strand increases with the increase of stress levels, corrosion time and concentration of chloride ion. The geometry of corrosion pit can be mainly divided into three types: the pyramid shape, spheroridicity shape and saddle shape. Meanwhile, the depth-width ratio of corrosion pit follows logarithmic normal distribution. It is also observed that the corrosion has a more significant effect on ultimate strength of strand than that on elastic modulus of strand. For slightly corroded strand, the constitutive model can be modeled as the elastic-hardening bilinear model. When the corrosion loss of strand exceeds the critical value, its constitutive relationship will degenerate into a single-linear model.
