ABSTRACT
The aging, extensive deterioration and structural and functional failures of a large number of highway bridges in North America and the high cost of repairs and replacements as well as the high negative impacts on users and neighboring communities are compelling many bridge owners to focus attention on the sustainability of their bridges. Most bridge design codes have focused primarily on satisfying life safety requirements and to a lesser extent the serviceability and durability requirements, which led to considerable demands for bridge maintenance due to extensive and premature deterioration. This situation will be further exacerbated by the changing climate and increased climatic loads and extreme weather events. Critical components of bridges should be designed and maintained to ensure high performance over a long time horizon that will ensure low probability of failure, long service life, low environmental impact and minimum life cycle cost. Such an approach will lead to sustainable and resilient bridges with enhanced socio-economic performance and improved environmental protection. However, the implementation of sustainability and resilience in the design and management of highway bridges is still in its infancy due to the lack of relevant performance indicators, lack of quantitative assessment approaches, lack of future climate data, and the competing nature of the social, economic and environmental pillars of sustainability. In addition, considerable levels of uncertainty are associated with the future climatic data and life cycle performance of bridges, which lead to different risks of failure that must be managed and kept at acceptable levels using different risk mitigation measures, such as reliable condition assessment, effective rehabilitation and climate change adaptation strategies, and reduction in demands on structures. Given the limited available resources and the emerging needs for sustainable and resilient bridges, a life cycle performance-based framework is proposed to help decision-makers implement life cycle performance-based approaches for the design and management of sustainable highway bridges.
