Study on the reactivity activation of steel slag through autoclaving curing

Feasibility study of partially replacement of cement and ground sand by ground steel slag (GSS) and ground granulated blast furnace slag (GGBFS) in producing prestressed high strength concrete pile (PHC) was conducted. The results showed that under normal curing (20 degrees C, 95% RH) and the steam curing condition (80 degrees C), GSS possessed less reactivity than GGBFS. However, under autoclave curing condition (180 degrees C, 1.0 MPa), the reactivity of G SS can be effectively activated. The autoclaving strength of the concrete made from 20% GSS with Blaine 550m(2)/kg, 55% cement and 25% ground sand could reach 89.0 MPa which is not only higher than that of GGBFS (82.8 MPa), but also higher than that of traditional PHC concrete (83.9 Mpa, 70% cement and 30% ground sand). It's feasible to produce PHC concrete by GSS with high fineness and optimized dosage.