Effect of application of metallurgical slag powders on physical and rheological properties of asphalt

•Three slags, electric arc furnace, blast furnace, and copper, were used as asphalt modifiers.•The performance of the slag-modified asphalts was characterized via physical and rheological tests.•The addition of the slags improved the short-term asphalt aging properties.•Rheological test results showed an enhancement in permanent deformation resistance of slag-modified asphalts. Metallurgical slags are residues that are obtained in the manufacturing and smelting processes of metals, such as steel and copper. However, their use is limited because they may cause environmental problems at their disposal sites. This study aims to evaluate the effects of the addition of slag on the properties of slag-modified asphalts using three different slag proportions (3, 6, and 10% by weight of asphalt). Electric arc furnace slag, blast furnace slag, and copper slag were used to evaluate the effects of the addition of slag on their performance properties via physical and rheological tests. The results showed an improvement in the consistency of the slag-modified asphalts, decreasing the penetration rate and increasing the softening point. An enhancement in the short-term asphalt aging characteristics was also observed with the addition of slag. Finally, the rheological test results revealed an improvement in the resistance to permanent deformation with the addition of slag in neat asphalt, whereas no statistically significant results were observed when the slag content was increased.