During the manufacturing of steel billets in the steel mills, iron oxide is formed as a flaky surface on the billets due to the hot rolling and cooling down process of the steel. Industrially, this surface is called billet scale. It is an industrial solid waste. In this study, billet scale is used as sand partial replacement in concrete. Six different percentage replacement of billet scale were used in this study. Concrete made with various percentages of billet scale were cured in two different mediums for the durability assessment, namely fresh water and water with higher salinity....