Hydration performance and compressive strength of alkali-activated slag using carbide slag and coking desulfurization...

Traditional activators are often reported to exhibit high cost and carbon emission, undermining the utilization of alkali activated slag (AAS) as sustainable binder from a technological point of view. This study investigates the performance of ground granulated blast furnace slag (GBFS) activated by coking desulfurization slag (CDS) and calcium carbide slag (CCS). The results demonstrate that the optimal compressive strengths achieved were 45.8 MPa at 28 days and 34.5 MPa at 3 days, meeting the standard for P·O 42.5 grade Portland cement. Microstructural characterization revealed that CCS dissolution provides Ca²⁺ and OH^-, promoting the formation of C-S-H, dominating the Ca/Si ratio and regulating the stability of products. While CDS contributes Na⁺ and SO₄^2-, enhancing the alkalinity of the activator, promoting the formation of ettringite, transforming C-S-H into C-N-S-H and accelerating nucleation from plane to three-dimensional growth. This study reported a new binder utilizing solid wastes and confirmed its feasibility as a sustainable alternative for ordinary Portland cement in applications.