The purpose of this work is to investigate the secondary Al slag (SAS) relating to its technical and environmental properties and, as consequence, to its compatibility with Portland cement matrix. This study may contribute to establish of SAS potential valorisation as secondary raw material (SRM) in concrete. DRX mineralogical analyses revealed that SAS includes transition alumina compounds, especial boehmite. The hydration process evolution and the hydration products nature in the Portland cement-SAS systems were studied by measurement of the Ca2+ concentrations and by DRX investigation. Also, was studied the ability of the Portland cement matrix to immobilize of the heavy metals contained of SAS, by MAF test.
Mixes of Cement:Sand: SAS with various sub-stitution ratios of sand by SAS, are carried out. SAS accelerates setting of cement pastes and decreases compression strengths of mortars. Treated SAS by washing causes a positive evolution of the mortars compression strengths up to 360 days.
The use of SAS as SRM in the concretes with low mechanical resistance - masonry blocks, road infrastructure -, can reduce the amount of secondary Al wastes and may contribute to environmental preservation.