Steel versus Steel-reinforced Concrete Bridges: Environmental Assessment

Bridge material selection has traditionally been b~ed on e.ngineering and economi~ criteria. With the increasing interest of the public, industry, and government m sustainable:: development, en~lronmental. assessment in construction is becoming more important. However, we need metrtcs and data on deSign alternatives for effective decision making. In this paper, we present results of a life cycle inventory analysis of steel and steel-reinforced concrete bridge girders, based on publicly available data. We find that for the initial constru~tion of equivalent designs for a particular location, a steel-reinforced concrete bridge g~neral~y .has lower enVironmental effects than a steel bridge. The expected design life of the two types of bndges is mfluenc~d. by wear and tear, but also by obsolescence. The uncertainty in bridge design life ~d 7 ~ta uncertamties m~e comparisons based on annualized environmental effects difficult. The ~teel bndge.s b.eneficial reuse and recych?g rates may result in lower annualized environmental effects. In particular apphcatlOns, however, one matenal might be preferred over the other due to engineering, aesthetic, or economic criteria, regardless of overall environmental effects.