Integrated Life-Cycle Assessment and Life-Cycle Cost Analysis Model for Concrete Bridge Deck Applications

Abstract

An integrated life-cycle assessment and life-cycle cost analysis model was developed and applied to enhance the sustainability of concrete bridge infrastructure. The objective of this model is to compare alternative bridge deck designs from a sustainability perspective that accounts for total life-cycle costs including agency, user, and environmental costs. A conventional concrete bridge deck and an alternative engineered cementitious composite link slab design are examined. Despite higher initial costs and greater material-related environmental impacts on a per mass basis, the link slab design results in lower life-cycle costs and reduced environmental impacts when evaluated over the entire life cycle. Traffic delay caused by construction comprises 91% of total costs for both designs. Costs to the funding agency comprise less than 3% of total costs, and environmental costs are less than 0.5%. These results show life-cycle modeling is an important decision-making tool since initial costs and agency costs are not illustrative of total life-cycle costs. Additionally, accounting for construction-related traffic delay is vital to assessing the total economic cost and environmental impact of infrastructure design decisions.