Properties of concrete with steel billet scale as sand replacement

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. Irrespective of curing age and curing medium, it was found out that 15% replacement of billet scale with fine aggregate is the optimum content. It was also found out that the billet scale proportion replacement is directly proportional to concrete slump and fresh density. Ultrasonic Pulse Velocity (UPV) increased with increase in strength. However, UPV stabilized with age of concrete, and, it was higher fresh water cured mixtures compared to those cured in saline water.