Circular Economy (CE) is presented today as the way forward to achieving a sustainable and carbon-neutral society. But CE is poorly quantified today. CE rebound effects and cradle-to-cradle analysis are not accounted for, as well as changes to more circular consumption patterns (e.g. sharing). This limits our capacity to understand and quantify the extent to which CE practices contribute to achieving a carbon-neutral economy.  Cement production is one of the most consumed products worldwide, with an annual global production that exceeds 4000 Mt. But cement is not the final application of the material. It requires the use of water and aggregates to form what we see around our infrastructure: concrete. Concrete is a composite material made from cement, sand, gravel water, and for special requirements, other admixtures and additives, and their recipes/proportions can be as complex as their value chains. But what are the CE options for concrete – and how can we finally close the largest CE loop of the chain? Can we recycle concrete, can we break down its components, to produce cement again? In this study, we have a mass balance approach to this question and try to answer it by using national Danish market data. The objective of this study is to track circular economy measures for the cement manufacturing industry in Denmark by understanding its value chain, identifying bottlenecks, and suggesting solutions to close the CE loops for the industry.

Acknowledgements: This research has been supported by the European Union's Horizon Europe research and innovation program, under grant agreement No. 101056862, CO2NSTRUCT project. This output reflects only the authors' view and the European Union cannot be held responsible for any use that may be made of the information contained therein.