Stochastic Model for the Chloride-induced Corrosion Service Life of Bridge Decks using Random Field Simulation

Chloride-induced corrosion is a primary cause of deterioration of bridge decks. This deterioration can result in reduced service life of a bridge and costly maintenance. Deterioration from corrosion can be seen on bridge decks as spatially variable. However, few research programs have considered the effect of spatial variability on the corrosion process. This paper presents a spatial time-dependent reliability model to predict the likelihood and extent of chloride-induced corrosion for bridge decks. The chloride ingress is modeled with concrete cover depth, surface chloride concentration, apparent diffusion coefficient and critical chloride concentration using a random field method. A bridge deck surface is discretized into a large number of elements to simulate the spatial variability of corrosion over the deck surface. This paper illustrates the modeling process which could be used by engineers and asset owners to better evaluate the life-cycle cost and maintenance strategies for their structures. As an example, a bridge deck of 12 m length and 10 m width is investigated.