Time-dependent probability assessment for chloride induced corrosion of RC structures using the third-moment method

• The analytical solution of corrosion initiation and cover cracking is improved.
• The third-moment based stochastic model of the two failure criterions is proposed.
• The effect of various influencing factors on the probability failure is discussed.

This paper presents the time-dependent probability of chloride-induced corrosion of reinforced concrete (RC) structures in marine environments. By using the third-moment (TM) method with improved analytical solutions, the stochastic models of corrosion initiation of reinforcing steel, along with the consequent surface cracking of concrete cover are proposed. The different effects of various influencing factors (including early-age micro crack or initial defect of concrete, etc.) on the time-dependent probability of corrosion initiation and surface cracking are also discussed. It is shown that the TM method developed in the paper is simpler and more efficient than traditional approaches such as Monte Carlo (MC) in analyzing the corrosion-induced probability. It is also shown that the distribution of influencing factors has little or almost no effect on the failure probability, whereas the mean and the coefficient of variation of basic variables affect it to various extents. Based on the detailed analysis, some conclusions with implications for engineering practice are drawn.