Laboratory evaluation of a complex treatment technology for reducing water absorption of the pavement subbase aggregate from the blast-furnace slag

Abstract

When smelting each ton of pig iron, approximately 500 kg of blast-furnace slag is formed and requires recycling. Air-cooled blast-furnace slag can be used for the manufacture of slag aggregate for the pavement subbase layers, as an alternative to natural stone aggregate. The wide use of slag in this area is limited by its high water absorption. This paper proposes a complex technology to reduce water absorption of slag aggregate. This technology includes selective crushing, which allows separating low-porosity aggregate grains from high-porosity ones, and impregnation of selected low-porosity grains with hydrophobic agent (surface hydrophobization). The results of a laboratory evaluation of this technology effectiveness are presented. Article also contains optimal parameters of this complex technological process which allowed to reduce the water absorption of the slag aggregate from 4.54% to 1.05%.