Bituminous pavement overlay of a porous asphalt mixture with ladle furnace slag: a pilot project.

This paper presents a pilot experience of applying a novel, high-performance and sustainable material for pavements: a Porous Asphalt (PA) mixture that incorporates Ladle Furnace Slag (LFS). The overlay of a thin surface layer of this material was applied to an existing bituminous pavement. The main investigative results included the validation of the laboratory mix design through large-scale mixing, laying, and compacting, followed by extensive laboratory and field tests. The results showed that the incorporation of up to 10% LFS in porous asphalt mixtures was feasible, with no need for preliminary physical or chemical treatments. The tests on the sustainable PA mixture revealed that its voids content, wear resistance, moisture susceptibility, and skid resistance were within regulatory limits. Neither workability nor compactability issues were observed in the execution of the pavement, and no ridging, rutting, cracking, or stripping were visible on the surface during the first months of use.