Performance and Durability of Porous Asphalt Mixtures Manufactured Exclusively with Electric Steel Slags

Abstract

Electric arc furnace slag (EAFS) and ladle furnace slag (LFS) are by-products of the electric steelmaking sector with suitable properties for use in bituminous mixtures as both coarse and fine aggregates, respectively. In this research, the production of a porous asphalt mixture with an aggregate skeleton consisting exclusively of electric steelmaking slags (using neither natural aggregates nor fillers) is explored. The test program examines the asphalt mixtures in terms of their mechanical performance (abrasion loss and indirect tensile strength), durability (cold abrasion loss, aging, and long-term behavior), water sensitivity, skid and rutting resistance, and permeability. The results of the slag-mixes are compared with a standard mix, manufactured with siliceous aggregates and cement as filler. The porous mixes manufactured with the slags provided similar results to the conventional standard mixtures. Some issues were noted in relation to compaction difficulties and the higher void contents of the slag mixtures, which reduced their resistance to raveling. Other features linked to permeability and skid resistance were largely improved, suggesting that these mixtures are especially suitable for permeable pavements in rainy regions. In conclusion, a porous asphalt mixture was produced with 100% slag aggregates that met current standards for long-lasting and environmentally friendly mixtures.

Performance-Based Characterization of Bituminous Mortars Prepared With Ladle Furnace Steel Slag

“…The basic properties of both the siliceous and the LFS sands are reported in Table 2 and the chemical composition of the LFS in Table 3. The main mineralogical composition of this LFS includes periclase, fluorite, portlandite, olivines, calcite, mayenite and some aluminates [21]. The mix formulas adopted for the preparation of the mastics and the mortars were obtained re-proportioning those of the corresponding mixtures [24] based on 100% passing of the mastic and the mortar through 0.063 mm and 0.125 mm sieves, respectively.…”

“…They also noted that LFS had higher bitumen absorption than the standard materials.Bocci [20] affirmed that the reuse of LFS in hot bituminous mixtures was feasible, in terms of mechanical behavior, water sensitivity and fatigue life. Moreover, in the leaching tests that were performed, the asphalt mixes with LFS released no metallic pollutants in water, except for aluminum, which was below the limits.Recently, Skaf et al [21] showed that porous asphalt mixtures manufactured with LFS in substitution of sand and filler produced similar results to the natural components in terms of abrasion loss, durability, permeability, permanent deformation and skidding resistance. In this research, the combination of LFS and EAF, the two main steelmaking slags, was performed to produce mixtures with especially suitable properties for rainy regions.…”

“…Recently, Skaf et al [21] showed that porous asphalt mixtures manufactured with LFS in substitution of sand and filler produced similar results to the natural components in terms of abrasion loss, durability, permeability, permanent deformation and skidding resistance. In this research, the combination of LFS and EAF, the two main steelmaking slags, was performed to produce mixtures with especially suitable properties for rainy regions.…”

“…In this research, the combination of LFS and EAF, the two main steelmaking slags, was performed to produce mixtures with especially suitable properties for rainy regions. EAF slag has previously shown its suitability in the manufacture of bituminous mixtures [22,23].In contrast to the promising results of those preliminary tests, compaction issues were also noted, due to higher void contents of the slag mixes [19,20] that slightly worsened their mechanical performance [21]. Further research is proposed to solve those issues, through in-depth examinations of the rheological properties of LFS mastic [20].…”

“…In contrast to the promising results of those preliminary tests, compaction issues were also noted, due to higher void contents of the slag mixes [19,20] that slightly worsened their mechanical performance [21]. Further research is proposed to solve those issues, through in-depth examinations of the rheological properties of LFS mastic [20].…”