Decision-making framework for interventions to minimise the life-cycle cost of corroding concrete structures

The ingress of chlorides into concrete structures can initiate corrosion, leading to reduced structural reliability and damage phenomena such as cracking and spalling of the concrete cover. This study presents a framework to identify the most cost-effective non-structural intervention from a pre-selected set of possible interventions to minimise the total maintenance cost over the intended lifetime of the structure. The maintenance cost involves the cost of the possible non-structural intervention, the expected cost of corrosion-induced spalling and/or cracking and the expected cost for a structural rehabilitation, which is imposed to be required upon exceeding a critical corrosion degree threshold. The framework explicitly models the influence of the interventions on the ingress of chlorides and integrates additional information from visual inspections and chloride profile measurements in a Bayesian framework. A case study of a reinforced concrete beam subjected to chloride ingress is considered where the decision-making framework is applied to determine the most optimal intervention. In a pre-posterior analysis, the decision-making framework is applied to investigate the influence of additional information, design parameters and the incorporated costs on the expected maintenance cost and proposed intervention strategy. The value of information of a chloride profile and visual observations is quantified.