Multiscale performance evolution and eco-efficiency analysis of sustainable alumina-rich cement composites cured by electric activation

The cement industry is a major source of global carbon dioxide (CO₂) emissions, driving the search for low-carbon alternatives. Limestone calcined clay cement (LC³), with its reduced clinker content and low-carbon profile during curing, offers a promising route. However, the lower early-age strength of LC³ related to low-clinker limits the use of construction materials. This study addresses the needs for carbon-reduction and low early-term strength, through the method combining clean-energy electric-activation curing (EAC) with low-carbon LC³ to establish a comprehensive carbon-reduction pathway from material formulation through curing. Result shows that increasing the curing voltage from 24 V to 72 V amplifies 7 h compressive strength by a factor of 7.7 in voltage-controlled experiments. A small impact shift is noticed that lower voltages encourage wrapped lateral precipitate of hydration gels, whereas higher voltages induce radial deposition, resulting in a denser microstructure. Life cycle assessment (LCA) indicates that the environmental impacts of EAC-LC³ reduced by 29.7 % (GWP), 11.5 % (ADP fossil), 33.7 % (AP), 28.4 % (EP), and 27.4 % (POCP), respectively, and the life cycle sustainable cost (LCSC) reduced by 13.8 %. Insights into voltage-modulated gel-formation mechanisms in alumina-rich systems, together with demonstrated environmental and economic benefits, support the adoption of this innovative low-carbon construction approach.