Environmental life cycle assessment (LCA) for design of climate-resilient bridges - a comprehensive review and a case study

The life cycle assessment (LCA) study of a bridge and bridge network would provide the environmental profile and hotspot information including the GHG emission of different life stages, among the components. Compared with a rapid adoption of Road LCA into the procurement process in the developed countries, Bridge LCA however remains a nascent area where a few studies conducted in North America. The critical issues of environmental profile, hotspots and benchmarks of bridges remain a challenge due to the complexity of bridge structures, data collection and unfamiliarity of LCA in the bridge community. To address the challenge, this study presents a comprehensive bibliometric analysis and review regarding life cycle environmental impacts assessment of bridge projects around the world to identify the research pattern in order to capture the areas of research needed inside this theme. As a proof of concept, this study continues with conducting an LCA case study of a Bridge Replacement Project on a Canadian signature highway, demonstrating the adoption of the LCA methodology and a framework to streamline the collection of data, to develop, present, and interpret the environmental impacts, in terms of the durability and service life of the bridge asset. The study found that stainless steel rebar decks outperformed black steel decks in terms of CO2 reduction by over 10%, with transport fleet impacts being a significant part of the bridge's overall environmental impact, highlighting the need for diverse functional units in bridge life cycle assessment studies.