Lifecycle Decision Framework for Steel Bridge Painting

Abstract

Bridge agencies seek to apply appropriate rehabilitation or maintenance treatments at the right time. For a specific treatment, improper timing can have significant adverse consequences: Premature application could mean wasteful spending by the agency even if road users and the community enjoy the benefits of a superior bridge condition, and deferred or delayed application can result in higher user or community disbenefits caused by poor condition and consequent reduced asset longevity in the long-term. For short-term decisions regarding the identification of the most cost-effective paint action at a specific time (do nothing, spot paint, overcoat, or recoat), the paper presents a methodology for developing a painting decision tree. For long-term decisions regarding the identification of the most cost-effective schedule over the superstructure lifetime, the paper demonstrates a methodology for developing a long-term schedule of painting activities. An analysis of the state of paint scheduling at a specific highway agency revealed that the current practice of complete recoating every 25 years may not be optimal. Instead, a painting schedule that includes the application of lower-level treatments (spot repairing and overcoating) can yield as much as a 19% reduction in the lifecycle cost and a 31.97% higher cost-effectiveness compared to the current practice.