Participants: Neustark, Empa, Kästli, Ara Region Bern, PSI
The objectives of this work package are:
This work package aims at demonstrating a mineral carbonation system, which allows to (1) store CO2 permanently in both primary and recycling concrete, and (2) reduce the energy demand and GHG emissions associated with both types of concrete considering the entire value chain.
This WP builds on the learnings acquired in the RECARB project, where only a part of the full system proposed here was demonstrated for seven days at scale, i.e., the mineral carbonation of fine RCA with particles size up to 16 mm. Beyond that, an experimental proof of concept material study revealed, that carbonation has the potential to alter the material properties of RCA in such a way, that cement contents in concrete mix designs can be reduced to the regulatory minimum. Since cement is responsible for more than 80% of the energy demand and GHG emissions of concrete, this approach has the potential to reduce both the energy demand and the GHG emission of future concrete significantly. To facilitate the dissemination of this knowhow and enable the Swiss industry to apply it, a more comprehensive approach is necessary.
Based on the findings of RECARB, several aspects have been identified which require further attention to increase the maturity of the value chain, to improve its environmental end economic performance and thus enable a rapid knowledge transfer and decarbonization of the Swiss concrete sector:
To sum up, the work package addresses the key environmental, economic and technological challenges by storing CO2 in all size fractions of RCA and concrete mixing water (i.e., scope expansion), by developing and demonstrating mix designs optimized in respect with their carbon footprint and a long-term demonstration of the technology.