Self-compacting concrete (SCC) with a 50% cement decrease is developed in this work. The feasibility of employing an alkali-activated blend of stainless steel slag (SSS) and fly ash (FA) as an alternative binder to cement has been established. SSS was processed using three distinct techniques. 35% SSS and 65% FA were used as precursors in the production of the binders, along with a hydroxide activating solution. For the creation of SCC, the 50% cement was used in place of this binder. The outcomes demonstrate high mechanical qualities and durability. The study demonstrates a decrease in cement consumption in the production of SCC by utilising two waste materials.