Performance optimization of single-component geopolymer-based grouting materials for road applications utilizing solid waste

Abstract To address the limitations of conventional grouting materials, such as insufficient fluidity and slow early strength development, the present study developed a single-component hydraulic early-strength geopolymer-based grouting material for road applications. Based on the principle of solid waste utilization, this study developed a material using a composite of slag (SL), fly ash (FA), and sulfate aluminate cement (SAC) as the main raw materials. Polycarboxylate superplasticizer and a proprietary filler (Filler A) were incorporated as functional admixtures. The study demonstrated that SAC significantly accelerated the pozzolanic reaction within the SL-FA system through alkaline activation. Furthermore, Filler A exerted a synergistic effect, significantly enhancing‌ the cementitious reaction kinetics. At a mass ratio of 3:2:1 for sulfoaluminate cement, SL, and FA, the composite grouting material exhibited exceptional comprehensive performance, achieving compressive strengths of 20.2 MPa (4 h), 34.5 MPa (1 day), and 51.2 MPa (7 days), along with an initial fluidity of 250 mm. Additionally, the material demonstrated micro-expansion behaviour at 7 days without bleeding, making it a highly workable, single-component, high early-age strength grouting material with promising potential for application in road infrastructure.