Scalable shear-exfoliated graphene for high-performance low-carbon recycled concrete

Scalable and sustainable construction materials are essential for decarbonizing the built environment and advancing the circular economy. Here, we present a robust, water-based method for producing defect-free, few-layer graphene via high-shear exfoliation of graphite, using a surface energy-matched solvent and a polycarboxylate stabilizer. Operating at ~8.4×10⁴s⁻¹, the process yields stable graphene dispersions (up to 5 g L⁻¹) compatible with cementitious systems. The resulting shear-exfoliated graphene (SEG) retains a pristine lattice structure and exhibits high colloidal stability, as confirmed by Raman and X-ray photoelectron spectroscopy. When incorporated into recycled concrete aggregate (RCA) concrete, SEG enhances compressive strength by 172.7% and toughness by 120%, while enabling a 40% reduction in cement use and saving 127.3 kg CO₂-equivalent per cubic meter. This scalable materials strategy transforms low-grade construction and demolition waste into durable, high-performance structural concrete-offering a practical, low-carbon solution aligned with global climate targets and sustainable infrastructure development.