Polymer-GGBS-cement amended reused blasting slag: Towards eco-friendly and resilient open-pit road surface.

Abstract

Growing industrialization and mining operation contributed to the generation of blasting slag and exacerbated demanding of open-pit road construction materials and dust emission. To reuse blasting slag and support eco-friendly open-pit road construction, this study aims to investigate the feasibility of polymer-ground granulated-blast-furnace slag (GGBS)-cement amended blasting slag as open-pit road surface. Specimens included GGBS-cement amended blasting slag powder (BG), GGBS-cement-polyacrylamide (PAM) amended blasting slag powder (BGP), GGBS-cement-carboxymethylcellulose sodium (CMC) amended blasting slag powder (BGC), and GGBS-cement-E+ dust suppressant amended blasting slag powder (BGE). Results indicated that the unconfined compressive strength of BGC with 0.75 % carboxymethylcellulose sodium reached a maximum of 8.50 MPa, whereas the BGP and BGE showed decreasing trends with increasing polymer content. The immersion stability of BGP, BGC, and BGE ranged between 83.22 % and 88.68 %, 81.63 % and 91.06 %, and 77.30 % and 71.44 %, respectively, with polyacrylamide contents of 0.025 %-0.10 %, carboxymethylcellulose sodium contents of 0.25 %-1 %, and E+ dust suppressant contents of 0.75 %-3 %. Furthermore, only appropriate amounts of PAM and CMC facilitated to resistance to wetting-drying cycles. Evaporation test showed that the water loss of BGP, BGC, and BGE was measured at 63.08 %, 71.03 %, and 65.07 %, respectively. The study elucidates the mechanisms improving mechanical performance and dust mitigation of amended reused blasting slag using scanning electron microscopy (SEM) and X-ray diffraction (XRD).