Alternative Supply of the Mineral Raw Material Needs of the Asphalt Industry by Metallurgical Slags

Abstract

With the growing demand for high-quality raw materials in the asphalt industry, finding sustainable alternatives to natural aggregates has become increasingly important. This study explores the potential of using metallurgical slags – specifically, blast furnace slag (BFS) and converter slag (CS) – as substitutes for traditional materials like basalt and andesite in asphalt mixtures.
Through a series of laboratory tests, we examined the performance of these slag-based mixtures in terms of stiffness, water resistance, deformation, and durability under thermal stress. The results were promising that both BFS and CS met or even exceeded standard technical requirements. CS showed superior stiffness and aging resistance, likely due to its alkaline properties that slow down bitumen degradation. Slag-based mixtures also demonstrated strong skid resistance and maintained their mechanical properties better than natural aggregates when exposed to extreme temperature changes.
These findings suggest that incorporating metallurgical slags into asphalt production could help address raw material shortages while offering environmental benefits, such as reducing CO₂ emissions and preserving natural resources. With comparable or even better performance than traditional aggregates, slag-based asphalt mixtures present a viable and sustainable option for the future of road construction.