Life cycle carbon emission assessment of large-span steel structures: A case study

Buildings take up a significant part of global carbon emissions and are a major contributor to the climate crisis. Large-span steel structures usually consume more materials, need more complex construction processes, and thus have a larger environmental impact. This study presents a comparative analysis of the life cycle carbon emissions of three typical large-span steel structures, i.e., a cable dome, a reticulated shell, and a suspendome, based on a design case. A tiered hybrid method using the process-based life cycle assessment for the processes with emission factors and using input-output-based life cycle assessment for the processes without emission factors is proposed to assess the life cycle carbon emissions. Comparisons on the carbon emissions of the three structures reveal that the cable dome is the best of the three, having the lowest steel consumption and the lowest carbon emissions. Although the component production phase appears to contribute most of the total emissions, the construction phase is also of considerable importance in alleviating the present emission pressure, especially for the cable dome and suspendome. Further analysis shows that carbon emissions of large-span steel structures are not simply linearly related to steel consumption and need to be considered as a separate design objective. This study pro-vides a useful reference for life cycle carbon emission assessment and low-carbon design of large-span steel structures.