Natural aggregates are consumed in large quantities in asphalt pavements, which cause a challenge for sustainable construction. To demonstrate the feasibility of replacing natural aggregates with steel slag, limestone, basalt and steel slag were used as coarse aggregates to formulate limestone asphalt mixtures (LAMs), basalt asphalt mixtures (BAMs), and steel slag asphalt mixtures (SAMs). The elemental composition and mineralogical characteristics of coarse aggregates were analyzed using X-ray fluorescence spectrometry (XRF) and X-ray diffraction (XRD). The quantitative characterization of aggregate properties was obtained using an aggregate image measuring system (AIMS). The bonding strength between coarse aggregates was compared using scanning electron microscopy (SEM), water immersion testing, and pull-off testing. This study investigated how different types of coarse aggregates influence the mechanical properties and pavement performance of asphalt mixtures. The results indicated that steel slag had a high gradient angularity index, high texture index, and numerous pores, and had high bond strength with asphalt. Compared with LAM and BAM, SAM exhibited superior mechanical properties and pavement performance, particularly in terms of resistance to water damage and low-temperature cracking.
Li et al. (Thu,) studied this question.