LCA of the improvement potential for construction and demolition waste: The role of site specificity and quality

Conference Dates

June 5 – 10, 2022


Construction and demolition waste makes up around 40% of the total waste generated in Denmark, and currently only around 36% of this is being recycled into high quality materials. This leaves a large improvement potential. The main objective of this study was to quantify the environmental impacts caused by different treatment options for asphalt and brick waste in Denmark, with a focus on the role of site specificity, quality, and technology readiness. To investigate this a case was established around the Danish company RGS Nordic. The environmental impacts of the included treatment scenarios were calculated using Life cycle assessment. The functional unit for both waste types was defined as: Management of 1 tonne of waste of varying quality as received after source segregation at the construction/demolition site in Denmark in 2021. The LCA covered 16 impact categories using the LCIA method, EF 3.0, with a special focus on Climate Change, Particulate Matter and Resource Use (minerals and metals) impacts. The overall results showed that reuse and recycling generally proved to be the environmentally best treatment options for both material fractions, while disposal/landfilling performed the worst. Crushing the materials and downcycling them into gravel showed mixed results by causing environmental savings within some impact categories, while generating impacts in others. Site specificity was found to play a large role, as transport contributed considerably to the generated impacts for most treatment scenarios. This finding is important as it can be hard to find space for treatment capacity in the dense city areas where C&D waste often is generated. The results also showed that the quality of the recycled materials was important to consider, since it can influence the results considerably. The study included a comparison between specific recycling technologies, where it was found that BSM performed remarkably better than conventional asphalt recycling. This was mainly caused by the amount of recycled material which can be added to the production processes. The results highlighted that there is not always one option that is best for the company, and the technology choice depends on origin of waste to treatment options. Further it was found that the recycling quality could be improved, through better value chain interaction with demolition companies. Since this can ensure a better source segregation which can help the materials keep their properties, so that they can be reused and recycled.

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