Mechanical properties and microstructure evolution of alkali-activated GGBS-fly ash-steel slag ternary cements

Multi-component alkali-activated materials have excellent performance, solving the problem of poor performance in part of single-component alkali-activated materials. This study investigated the mechanical properties and microstructure evolution of alkali-activated GGBS-fly ash-steel slag ternary cement (ATC). Results showed that incorporating steel slag considerably increased the fluidity and prolonged the setting time of the alkali-activated GGBS system, while the compressive strength only slightly decreased. Incorporating steel slag into the alkali-activated fly ash system effectively enhances the compressive strength of ATC. This is attributed to the C 2 S and C 3 S in steel slag participating in the formation of C-(N)-A-S-H gel products, improving the porosity and microstructure of ATC. Furthermore, ATC exhibits excellent compressive strength, pore structure, and microstructure compared to the alkali-activated GGBS-fly ash system, while also demonstrating similar properties to the alkali-activated GGBS-steel slag system. • Incorporating SS improved the compressive strength and pore structure of GGBS-FA system. • Incorporating FA and SS enhances fluidity and prolongs the setting time of ATC. • C 2 S and C 3 S in SS can promote the formation of C-A-S-H gels in ATC. • ATC's good mechanical properties relate to similar GGBS reaction products (C-(N)-A-S-H).