16 - Probabilistic modeling of chloride diffusion in repaired reinforced concrete structures

Abstract

The durability of reinforced concrete (RC) structures is a crucial aspect of infrastructure maintenance, as it directly affects the safety and serviceability of these structures. Therefore, it is of utmost importance to understand the degradation processes and develop appropriate repair strategies. However, probabilistic modeling of degradation processes in repaired concrete structures is still at an early stage, especially in the context of chloride-induced corrosion. Within this context, the aim of this chapter is to present a methodology for modeling chloride diffusion in repaired RC structures and predict their service life. The study focuses on the probability of corrosion initiation associated with the serviceability limit state. A probabilistic approach using Latin Hypercube Sampling and Polynomial Chaos Expansions is applied to account for and propagate uncertainties and estimate the risk of corrosion initiation. Both corrective and preventive repair strategies could be modeled. A studied case study shows that the probabilistic evaluation based on the polynomial chaos expansion method is efficient and accurate. The probability of corrosion initiation can be reduced by using some repair strategies, such as shorter repair intervals or deeper replacement of the concrete. Furthermore, the proposed approach allows the evaluation of several preventive repairs and thus the derivation of an optimal maintenance schedule based on the threshold probabilities given by the acceptable risk levels of the end user. This provides a more reliable and accurate basis for infrastructure maintenance and decision-making planning.