Comparison of Deterministic Calculation and Fuzzy Arithmetic for Two Prediction Model Equations of Corrosion Initiation

The existing deterministic solution for prediction model of corrosion initiation cannot reflect input variable uncertainties very well. Thus there is a growing tendency for a stochastic model based on the probabilistic method to be developed and applied, This paper presents an approach to the fuzzy arithmetic based modeling of he chloride-induced corrosion of reinforcement in concrete structures that takes into account the uncertainties in the physical models of chloride penetration into concrete and corrosion of steel reinforcement, as well as the uncertainties in the governing parameters, including concrete diffusivity, concrete cover depth, surface chloride concentration and critical chloride level for corrosion initiation. There are a lot of models for predicting the onset time of reinforcement corrosion of structures exposed to corrosion environment. In this work, the RlLEM model formula and Crank’s solution ofFick’s second law of diffusion are used. The parameters of the models are regarded as fuzzy numbers with proper membership function adapted to statistical data of the governing parameters, while the fuzziness of the corrosion time is determined by the fuzzy arithmetic of the interval arithmetic and extension principle. An analysis is implemented by comparing the deterministic calculation with fuzzy arithmetic for the above two prediction models.