ABSTRACT
Chloride attack is one of the significant problems affecting the durability of concrete structures. The time for chloride ions arriving reinforcing bars is an indicator to predict service life in the view of the rebar corrosion. The diffusivity of chloride ions in concrete is a key factor for the prediction of service life, but it is inherently distributed at a large variation. Considering the diffusivity as a random variable allows us to analyze the inherent variation. A large number of mortar samples are subjected to a test measuring the diffusivity using a miniature device complying with NT BUILD 492. The statistical distribution of the diffusivity can be developed with the measurements. Applying Fick’s 2nd law with the diffusivity results in calculating the probabilistic life span of a given structure. This study finally proposes chloride-attack fragility by evaluating the probability of failure at life expectancy.
