Digital Tool for Carbon Assessments in Bridges

Most of the BIM models for bridges have been modelled in Rhinoceros 3D and Grasshopper, but there is a missing link between the BIM models and the carbon calculation tool which needs to be addressed. To solve this problem, the Mott MacDonald team have developed a digital tool within the Grasshopper environment using the C# programming language. The main advantage of Grasshopper lies in its parametric design capabilities, which enable changes to be implemented very quickly and easily. This plug-in creates a direct link between the BIM models and Mott MacDonald’s in-house carbon portal, allowing users to conduct bridge carbon assessments using the bridge-specific carbon database. The database contains embodied carbon factors for common materials such as concrete and steel, as well as other components such as expansion joints and bearings. This includes emissions related to the supply, transport, manufacture of raw materials, as well as emissions from transportation and site activities. A carbon assessment can be done for each of the elements, and for the required design and construction stages. Users just need to connect the individual bridge elements to the corresponding materials and this tool will automatically calculate the volume and carbon emissions. Users can compare carbon data between different design options directly in the Grasshopper environment during the optioneering stage, and track carbon emissions throughout the design and construction stages without the need to repeat carbon calculations.