Performance Enhancement of Alkali-Activated Electric Arc Furnace Slag Mortars through an Accelerated CO2 Curing Process

The use of electric arc furnace slag (EAFS) as sole precursor to produce alkali-activated mortars has been experimentally investigated. EAFS, a by-product the steel recycling industry, is coarse material with unevenly distributed and size-extensive particles. Milling EAFS was required achieve cement-like sized powder before it could be used precursor. Different combinations sodium hydroxide (NaOH) silicate (Na2SiO3) were used, by varying Na2O/binder concentration (4%, 6%, 8%, 10%, 12%) SiO2/Na2O ratio (0, 0.5, 1.0, 1.5, 2.0, 2.5) maximize mechanical performance. alkaline solutions prepared 24 h prior mixing unify temperatures for all mixes. results showed that strength development are directly proportional. maximum 28-day compressive obtained, after being subjected an initial thermal curing at 80 °C, 9.1 MPa in mixes 4% 2.5 SiO2/Na2O. However, additional 28 days accelerated carbonation, (i.e., 31 compared 3.9 uncarbonated mixes, corresponding 800% increase) obtained 12% 1.0 SiO2/Na2O, respectively, thus showing alteration optimal activator contents.