Concrete builds the modern world, yet its production remains fundamentally unsustainable. Over 30 billion tonnes of concrete are produced annually, fuelling a one-way flow of resource extraction and accumulation of CO2 emissions and inert demolition waste. Current recycling practices predominantly downcycle waste into low-grade applications, limiting environmental benefits and stalling progress toward a circular economy. Here, an electrochemical-driven recycling (ER) strategy is proposed that upcycles concrete waste into high-value resources, including pristine aggregates and zero-carbon clinker precursors. The ER process selectively decomposes hydrated cement phases, demonstrating the chemical reversibility of hydration products and enabling regeneration of clinker precursors. The recovered substances are recombined to create reversed Portland Cement and reversed concrete that match conventional counterparts in both composition and performance. Validated at pilot scale (19. 2 t/year), the ER strategy achieves 95. 4 wt. % circularity and reduces global warming potential from 448. 4 to -4. 6 kg CO2-eq/m3, rendering the concrete carbon-neutral across its full life cycle. Cost analysis indicates competitiveness with conventional production, offering up to 94. 8/m3 in net savings under high landfill pricing. By closing both material and carbon loops, this work charts a scalable path toward circular concrete, where demolition no longer marks an end, but a beginning.
Lyu et al. (Wed,) studied this question.