Embodied carbon of BIM bridge models according to the application of off-site prefabrication: Precast concrete applied to superstructure and substructure

Abstract

Embodied carbon (EC) changes of bridges using PC and RC, were analyzed using BIM and One-Click LCA. Identically shaped, concrete bridges (RC, PC, superstructure-only PC, and substructure-only PC) were modeled; the bills of quantity were extracted and input into the LCA software for EC comparison. As a result, it was found that applying PC instead of RC is not necessarily a guaranteed method to reduce the EC of bridges. Sensitivity analysis on the EC according to concrete waste and material transportation distances of all models were conducted. References from a carbon perspective were presented for applying PC separately to superstructure and substructure. As a result, solutions for the application of PC were derived considering the changes in concrete waste and transportation distance of concrete inputs. Conclusively, it was analyzed that substructure-only PC is effective in reducing EC overall, regardless of the amount of concrete waste and transportation distance of inputs.

Keywords

• Off-site construction
• Precast concrete
• Carbon footprint
• Embodied carbon
• Building information modeling
• Bridge lifecycle assessment