Dimensional stability of electric arc furnace slag in civil engineering applications

Dimensional stability of manufactured aggregates represents a matter of interest for many applications in civil engineering. Past results evidenced how steel slag might be affected by potential swelling, due to several concurring causes linked to the presence of free lime and periclase in their chemical composition. In this work, a detailed analysis about physical and chemical properties of Electric Arc Furnace slag (EAFS) is developed, using thermogravimetry, scanning electron microscopy, X-ray diffraction and porosity analysis. The efficiency of a commonly used method for slag treatment on reducing its swelling-potential is also experimentally assessed and confirmed, through expansion tests carried out in an experimental apparatus developed specifically for this scope, based on steam diffusion within the test sample. Lastly, a maximum allowable limit for slag swelling is proposed for some applications of interest.