The Carbon Footprint of Bridges

Sustainability, climate change issues and carbon emissions have recently become more prominent. To limit carbon emissions and reduce them we need to understand where and how much we use. The bridges and viaducts on major infrastructure projects have a high intensity of carbon compared to the average per kilometre. In this paper the carbon footprint of a range of current bridges and viaducts are outlined relative to cost, length, area, material and traffic type to give a benchmark for future reductions and to outline areas where improvements can be made. Engineers have often kept track of material quantities to estimate cost; the carbon content of a bridge can be calculated from the primary material quantities and construction methods. Information from a database of bridges is used in this research to estimate the capital carbon of 200 bridges. The data show the trends for different bridge loading types, materials and spans. The database can be used to assist with the reduction of carbon in bridges by benchmarking current carbon footprints.