Carbon dioxide evaluation in a typical bridge deck replacement project

Abstract

Different structures can exhibit very different characteristics in terms of embedded carbon dioxide emissions. It is therefore important that the carbon accumulation of a particular type of structure over its intended service life is properly understood before targeted measures can be taken to reduce any adverse effects. For the same type of infrastructure, considerations may vary markedly for different types of work. Within the bridge engineering sector, fibre-reinforced polymer deck has been increasingly used in deck replacement applications. However, study on its environmental performance is limited. This paper considers a typical UK highway bridge deck replacement project and evaluates two different options, including the fibre-reinforced polymer option, in carbon terms. In order to provide more general information to bridge engineers, the bridge is assumed to carry an ‘average’ volume of traffic across the highway network where it is most likely to be present. Both the embodied carbon dioxide and carbon dioxide emissions from future maintenance activities are considered. Since traffic diversion can only be considered on a project-by-project basis, parametric study is carried out to further investigate its effects. Based on the results, good practices are identified to enable engineers to reduce their carbon dioxide footprint. Uncertainties and limitations of the results are also discussed.