This research has a purpose to study the mechanical properties of concrete when using steel slag as an alternative for sand material in the mixture of concrete quality f’c 25 MPa. The research consisted of 6 tests, they were permeability, porosity, shrinkage, compressive strength, Scanning Electronic Microscope (SEM) and Energy Dispersive Spectrometry (EDS). The steel slag used were 0 % and 3…