Performance Effects of Mixed Mortars with Ladle Furnace Slag as a Replacement for Hydrated Lime

Amongst the byproducts of steel industry is ladle furnace slag (LFS), with a chemical composition similar to limes, especially in the high content of calcium oxide and hydroxides. Its binding potential is improved with finer texture, making it viable for use as a supplementary cementitious material (SCM). Therefore, this study investigated the effects of a total replacement of hydrated lime (HL) for LFS in masonry mortars, also exploring whether pozzolanic addition of metakaolin (MK) could enhance it, tested both at 28 and 180 days. The experimental results, obtained at 28 and 180 days, showed that the replacing HL for LFS improved the mechanical properties of the mortars, due to the greater amount of compounds of LFS also present in the OPC, but not in the HL, such as Fe2O3, Al2O3 and SiO2. These findings suggest the potential of LFS for application in masonry mortar promoting strategies of circular economy.