为积极响应国家“双碳”战略，破解单掺水泥这一流态固化土高碳化瓶颈。本研究首次提出以“矿渣(GBFS)-钢渣(SS)”协同部分替代水泥用于流态土固化的胶凝新体系。对于不同矿渣-钢渣掺量下的水泥基流态固化土通过流动扩展度、凝结硬化时间、无侧限抗压强度及微观结构(XRD、SEM)等试验，系统探讨二者对流态固化土性能的协同作用机制。结果表明：钢渣比例降低导致流动扩展度下降(216～164 mm)且下降速率增大，矿渣比例增加显著缩短初、终凝时间。各配比下流态固化土初凝时间为189～215 min终凝时间为385～410 min。抗压强度受矿渣与钢渣比例显著影响，当钢渣、矿渣和水泥的质量比为1:4:5时，28 d抗压强度达峰值3.05 MPa，较单掺体系(S50-G0)提升23%。微观结构分析显示该配比火山灰反应最充分，孔隙率最低，生成更多的水化产物(C—S—H、C—A—H、AFt等)，形成了致密网状结构。矿渣与钢渣协同部分替代水泥可优化流态固化土的性能。

To advance China’s “dual-carbon” strategy and address the high-carbon bottleneck of cement-only binders in flowable solidified soil (FSS), this study proposes, for the first time, a novel cementitious system in which ground granulated blast-furnace slag (GBFS) and steel slag (SS) jointly and partially replace cement for FSS stabilization. Flow spread (slump flow), setting time (initial and final), unconfined compressive strength (UCS), and microstructural characteristics (XRD, SEM) were tested to systematically elucidate the synergistic mechanism of GBFS and SS on FSS performance. The results show that decreasing the SS proportion reduces the flow spread (216～164 mm) and accelerates its rate of decline, while increasing GBFS markedly shortens both initial and final setting times. Across all mixtures, initial and final setting times ranged from 189～215 min and 385～410 min, respectively. Compressive strength was strongly governed by the GBFS-SS proportions; at a SS:GBFS:cement mass ratio of 1:4:5, the 28-day UCS peaked at 3.05 MPa, a 23% increase over the single-admixture system (S50-G0). Microstructural analyses indicate that this mixture exhibited the most complete pozzolanic reaction, the lowest porosity, and a greater abundance of hydration products (C—S—H, C—A—H, AFt), forming a dense interlocked microstructure. These findings demonstrate that jointly and partially replacing cement with GBFS and SS effectively optimizes the performance of FSS.