Pozzolans are siliceous or siliceous and alumina materials that have no or low adhesive value on their own but react with calcium hydroxide in the form of very fine particles at ordinary temperatures and in the presence of moisture, producing compounds whose structure is somewhat similar to the compounds produced by the hydration of Portland cement. In this study, first the slag exiting the furnace was rapidly cooled with water, then the slag was ground until its size was below 125 microns. XRD, XRF and FESEM tests and other tests were performed on the samples, and if necessary, other tests were performed. The powdered slag was replaced with cement in the self-compacting concrete mix design with replacement percentages of 0, 5, 10, 15, 20 and 25. Also, fresh concrete tests including slump flow, J-ring, L-box, V-funnel were conducted for all samples and hardened concrete tests including compressive strength, direct tensile strength, water permeability and accelerated chloride ion permeability were conducted for the samples. The results show that the 28-day tensile strength for both M1 and M2 samples decreased with increasing percentage of steel slag powder, and this amount is almost similar for both samples. and only when adding 10% of steel slag powder, the 28-day tensile strength for M1 sample is higher than this amount for M2 sample. Also, the 72-hour water permeability depth at the age of 28 days for both M1 and M2 samples increased with increasing percentage of steel slag powder.