Reliability based corrosion damage assessment for concrete bridge decks under a changing climate

Abstract

A changing climate may alter the environment during the concrete structures’ service life, especially in the longer term. According to the latest Intergovernmental Panel on Climate Change (IPCC) climate projections that temperature and carbon dioxide concentration in the atmosphere are likely to increase significantly by the end of this century. These changes may cause an acceleration of carbonation-induced deterioration processes and consequently a decline of the safety, serviceability and durability of concrete infrastructure. Carbonation-induced deterioration of Reinforced Concrete (RC) bridge decks under a changing climate is investigated in this study. Two latest IPCC climate projection scenarios, i.e. RCP 8.5 and RCP 4.5 emission scenarios, are used here representing possibly high and medium greenhouse gas emission scenarios. The spatial time-dependent reliability analysis is used to include not only the uncertainty of climate projections, deterioration processes and predictive models, but also the spatial variability in material properties and dimensions. The likelihood and extent of corrosion damage is estimated by tracking the evolution of the corrosion process across a bridge deck using Monte Carlo Simulations, and it is more or less affected by the changing climate depending on locations. Case studies of RC bridge decks are presented considering effects of construction methods, climate conditions and design specifications for Australian and Chinese bridges. The findings provide a basis for the development of climate adaptation through the design of concrete bridges, as well as an assessment of the optimal timing and extent of maintenance measures of concrete bridge asset management plans.