CO 2 utilization for concrete production: Commercial deployment and pathways to net-zero emissions.

Approximately 10 % of global anthropogenic CO2 emissions arise from the cement and concrete industry driven by urban expansion and a constant need for infrastructure renewal. Reusing waste CO2 to make new construction materials produces circular carbon flows and constitutes a key step toward a carbon-negative economy. To establish a holistic view of the field, this paper examines upscaled technologies with industrial deployments for utilizing CO2 in manufacturing cement-based materials and analyzes their interplay for attaining net-zero emissions (NZE) in the concrete sector. By scrutinizing the status quo, it suggests that NZE agendas should be diversified catering to the wide-ranging built products. Small-sized precast elements and lightweight components lead the way in carbon-neutral manufacturing, while the market-dominating ready-mix concrete is by far difficult to decarbonize and relies on the incorporation of pre‑carbonated ingredients, preferably sourced from alkaline wastes, to leverage large-scale CO2 utilization. To expedite the race to NZE, it is necessary to combine the development of CO2 utilization and low-CO2 cement to create decarbonization strategies tailoring for individual products. In this regard, the paper reveals credible pathways and research needs to facilitate their implementation in sustainable construction.