Assessing the Condition of Concrete Bridge Decks Subjected to Corrosion and Fatigue in a Changing Climate Using Nonhomogeneous Markov Processes

Abstract Bridge deterioration is influenced by material and structural design properties, traffic-induced fatigue, climatic and environmental loads, and maintenance history, all of which may be affected by population growth and climate change. As a result, deterioration rates are nonstationary over a bridge’s service life, limiting the applicability of homogeneous Markov chain models commonly used by infrastructure asset managers. This study presents a nonhomogeneous Markov process framework that integrates mechanistic models to evaluate time-dependent deterioration of RC bridge decks under changing climate and environmental conditions. The framework accounts for chloride-induced corrosion, carbonation, and fatigue, combined with future climate and traffic projections. Our modeling shows that environmental corrosivity is the primary driver of deterioration, with decks made of normal-strength concrete and carbon-steel reinforcement reaching advanced deterioration states in about 30 years under severe conditions. Chloride ingress initiates corrosion much earlier than carbonation, and the pit-to-fatigue crack transition can occur between 10 and 40 years, shortening with higher corrosivity, increased traffic, and rising temperatures. The influence of climate change is more significant before corrosion initiation than during propagation. These findings provide infrastructure asset managers with a basis to predict condition states under evolving climate conditions, supporting improved maintenance planning and extending the service life of bridge structures.