Abstract:Based on Fick second law of diffusion and a pitting depth and configuration model, the corrosion initiation time and the remaining area of prestressing steel were analyzed using Monte Carlo method. The deterioration of bending resistance was calculated according to the corrosion analysis results. The lifecycle reliable probability of bending was calculated using time variant load model and Monte Carlo method. The probability results were fitted by Weibull distribution function, which showed a good accordance. The influences of important parameters of beam depth, concrete cover thickness, surface chloride content, chloride diffusion coefficient and corrosion current density on structure deterioration were analyzed. The results show that beam height has minor impact on durability, while concrete covering demonstrates large influence on lifetime function. Further countermeasures should be taken with respect to surface chloride content, chloride diffusion coefficient and corrosion current density.