Probabilistic corrosion condition assessment of a tunnel structure

Reinforced concrete structures constitute the basis of our infrastructure. Their functionality and structural safety is essential to maintain our mobility and the industrial performance of our societies. Unexpected maintenance can lead to serious economic consequences. Most industrial countries are faced with the fact that the reliability of their infrastructure has decreased over the past decades due to ageing and associated durability issues. Most often reinforcement corrosion is the major problem with respect to ageing phenomena observed. Therefore, data from corrosion inspection and their implementation in probabilistic corrosion condition assessment are considered to be of major importance to assist engineers in the maintenance process. Reliable information about the corrosion condition state can be derived through half-cell potential measurements. The half-cell potential measurement method is an easy to apply nondestructive measurement method to detect ongoing corrosion. The procedure on how to update the service life based on a probabilistic treatment of measured half-cell potentials is presented in a case study of a chloride-contaminated reinforced concrete structure. Besides the chosen probabilistic model, major impact on the accuracy of the updated service life has the evaluation of the half-cell potential measurements.