Life-cycle maintenance strategy of bridges considering reliability, environment, cost and failure probability CO2 emission reduction: A bridge study with climate scenarios

Climate change significantly affects existing infrastructure by enhancing the deterioration of concrete structures. As the number of repairs and strengthening increases during the service life of a bridge, the cost and environmental impact gradually increase as well. This study aims to propose a framework with climate adaptability considering reliability, environment, and cost, to realize the optimization of the life-cycle maintenance strategy of bridges under climate change. In this study, four preventive maintenance and four essential maintenance of bridges were comprehensively considered, and the reliability, environmental impacts and cost of the bridge at the maintenance stage were quantitatively analyzed. By using the decision tree method, the optimal strategy of bridge life cycle maintenance and reinforcement under climate change scenario was proposed, with the environmental impacts, environmental cost, economic cost and comprehensive cost as the optimization objectives, respectively. Finally, a failure probability calculation model of emission reduction target of bridges was estimated, based on the CO2 emission reduction targets by China in the Paris agreement. To demonstrate the applicability of the proposed framework, a typical highway bridge was taken as an example. It can be observed from the results that the maintenance strategies determined with different optimization objectives show great differences in environmental and economic costs. With the deepening of climate scenario, the failure probability of bridge emission reduction of maintenance strategies with diverse optimization objectives will increase by 10%–20%. The findings highlight the climate adaptability assessment framework is of significant for optimizing the maintenance budget and environmental impact of aging bridge structures in China, and is expected to support decision-making for bridge maintenance under the influence of climate change.