The performance of steel-making slag concretes in the hardened state

•Study a concrete that blends two slag aggregates as an adequate raw material.•Making more deepen the knowledge of mix proportioning of slag concrete.•Study of density and workability of designed slag concrete.•Performance of slag concrete in a hardened state.•Assesses the slag concrete against the Spanish structural concrete standard.

The use of oxidizing slag from electric-arc furnaces as an aggregate is a sustainable option in the manufacture of concrete, the performance of which is similar to an ordinary aggregate concrete. This study examines the reuse of two different types of oxidizing slag in concretes designed for use in structural components and compares their performance against relevant specifications contained in current working standards. Fundamental aspects are discussed, among which density and workability that are related to the proportioning of the concrete and its mechanical and physical properties. The results show that overall concrete quality is maintained and that its performance is acceptable for the proposed application.