Recycling solid waste into artificial aggregates represents a promising approach for large-scale solid waste management and alleviating the shortage of natural construction materials. However, the preparation and curing processes play a decisive role in the performance of aggregates. To meet the requirements of early-age strength of aggregates and synergistic load-bearing behavior with hardened cement matrices, this study developed a novel solid waste-based artificial aggregate using steel slag(SS) and recycled concrete fines (RCF). Polypropylene fibers (PPF) were incorporated, and a combined process of compaction granulation and CO 2 curing was employed. The results show that the optimal performance was achieved with a mix proportion of RCF:SS = 60:40, 1% PPF content, and a compaction pressure of 89 MPa, which increased compressive and splitting tensile strengths by 152.68% and 81.81%, respectively. Energy evolution analysis further revealed that this mix proportion enhanced the total energy, elastic strain energy, and dissipated energy by 157.30%, 135.93%, and 203.72%, respectively. These improvements are attributed to the synergistic effect of fiber bridging and compaction-induced densification, which together enhance material toughness and energy dissipation capacity. Additionally, calcium carbonate crystals formed during CO 2 curing effectively filled internal pores and strengthened the fiber-matrix interface. In summary, This study introduces the incorporation of polypropylene fibers into steel slag-recycled concrete fines-based artificial aggregates, achieving synergistic regulation of their microstructure and mechanical properties through combined compaction and CO 2 curing. In perspective, this approach enables the high value integral utilization of solid wastes and provides an eco-friendly technical strategy and theoretical guidance for the production of high-performance, low-carbon artificial aggregates. • Solid wastes are integrally recycled into artificial aggregates by compact granulation and CO 2 curing. • Fibre addition into artificial aggregates improves the stress-strain properties of aggregates. • Reinforced artificial aggregates modify the stress-strain properties of cement matrix. • Energy evolution characteristics of cement specimens with reinforced aggregates are improved.
Shuai et al. (Sun,) studied this question.