25 Years Working with Green Steel Slag Concrete

Industrial production of iron and steel within Spain has historically been situated in the north area of Spain. Although a major economic activity for the region, the industry also generates large volumes of waste that have hitherto been dumped in unsightly landfill sites. Over 25 years ago, a group of engineers and researchers from the same area set themselves the challenge of regenerating this waste. In this study, the advances developed in the technology of green slag concrete are reviewed, focusing on the expertise that the research group has accumulated over the past 25 years. Electric arc furnace slag is a stony material that is now often used as aggregate in hydraulic and bituminous mixes. Its use in hydraulic cement-based materials and the important properties of slag aggregates for mix workability are analyzed. Likewise, the mechanical behavior and the durability of slag concrete specimens is presented, paying special attention to expansive compounds and to the performance of electric arc furnace concrete in marine environments. In addition, real scale elements manufactured with slag concrete and their behavior are analyzed, as well as the advantages of applying current standards to their design. Finally, new lines of research are discussed for the use of electric arc furnace slag in cement-based materials.