A simplified and practical approach regarding design for durability of reinforced concrete structures based on probabilistic modeling of chloride ingress

There is a clear trend towards design for durability of reinforced concrete structures using probabilistic modeling. However, such an advanced approach is considered to be useful for scientists rather than practitioners dealing with real structures. Although a probabilistic approach is essentially correct, the observed lack of a sufficient amount of reliable statistical data on input parameters as well as an objective use of this data will limit a widespread application in practice. In this paper an attempt is made to develop simple mathematical expressions based on a significant number of probabilistic calculations, taking into account the variability of all model parameters. Eventually, this exercise has resulted into practical formulas for 3 levels of probability of corrosion initiation, P-i = 5, 10 and 20%. Using these formulas, for any arbitrary choice of cover depth the corresponding apparent chloride diffusion coefficient can be calculated, the combination corresponding to the desired probability level within a narrow range of 0.5% in most situations.