Low Regret-Based Design and Corrosion Management for Steel Roadway Bridges

This paper describes a low regret-based adaptive decision-making methodology for evaluating alternative design and corrosion management strategies for steel roadway bridges despite limited site-specific knowledge of the actual corrosiveness of the environment. To illustrate the method, an example is provided, in which design options include whether using metallizing or not as a corrosion protection measure and its time of application. While in a mild environment, unpainted weathering steel might show little degradation, in case of realization of a severe environment, for example, due to extensive use of de-icing salt during winter, using this material without protection can be problematic as doing so might result in higher management costs or even catastrophic failures. On the contrary, the realization of a mild or moderate environment after utilization of the expensive galvanized/metallized steel or early adaptation of preventive measures can also be viewed as suboptimal. Another strategy is resorting to adaptive solutions, beginning with a less expensive option until the actual environment is more evident. Willing to minimize the "maximum sense of loss", in the methodology applied here, regret is combined with the real optionmethodology and implemented in the decision-making framework. In this way, the methodology quantifies the desire of decision-makers to minimize the sense of loss associated with having made the wrong decision.