Spatial variability-based corrosion risk assessment and strategy of repair and maintenance for RC structures

A corrosion risk assessment model (CRAM) of reinforced concrete structures subjected to marine environment is presented. The spatial variability of parameters, which are decisive for the durability performance, is modelled probabilistically in terms of sample statistics, which may be assessed by testing of existing structures. The result of the chloride profile test is suggested to update the input model parameters for future structural condition prediction. The requirements to the service life performance are formulated in terms of the probability that the structure will be in a certain condition class after a given service time. Further, it is demonstrated how optimal strategies for repair and maintenance of concrete structure subject to chloride ingress can be determined on the basis of corrosion risk classes. The present method to plan optimal repair strategy is illustrated by an assessment case. For structures with large concrete surface exposed to chloride-laden environment, both spatial and temporal characteristics of deterioration are suggested to consider in condition assessment based on field inspection.