流态固化土因其高流动性、自密实、强度可控等特点可解决回填场地狭小、回填空间狭窄等填筑工程难题。流态固化材料主要包括胶凝组分和流动组分,本文主要对流态固化淤泥的胶凝材料配比和机理进行研究。采用矿粉和水泥作为基础胶凝材料,通过双掺试验确定激发剂生石灰和硅酸钠的适宜掺量,借助Design Expert软件进行响应面分析,得到复合胶凝材料的优化配比；通过XRD和SEM试验得到固化淤泥的产物种类和微观结构,分析固化机理。结果表明,复合胶凝材料(CCM)水泥：矿粉：生石灰：硅酸钠的优化配比为38:42:9.7:6.5,采用CCM的流态固化淤泥的流动度和强度均优于仅采用水泥的流态固化淤泥。CCM固化淤泥的水化产物主要包括水化硅酸钙凝胶和钙矾石,水化产物包裹土颗粒并填充孔隙,显著提高了流态固化淤泥的强度。CCM的固化淤泥强度提高包括水化作用、碱激发火山灰反应、离子交换作用、微膨胀和填充作用等。

Fluidized solidified soil, due to its high fluidity, self-compaction, and controllable strength, can solve filling engineering problems such as narrow backfill sites and narrow backfill spaces. Fluid solidification materials mainly include cementitious components and flow components. This article mainly studies the cementitious material ratio and mechanism of fluidized solidification sludge. Using slag and cement as basic cementitious materials, the appropriate dosage of activator quicklime and sodium silicate was determined through double mixing experiments. Response surface analysis was conducted using Design Expert software to obtain the optimized ratio of composite cementitious materials; Obtain the types and microstructure of solidified sludge products through XRD and SEM experiments, and analyze the solidification mechanism. The results showed that the optimized ratio of composite cementitious material (CCM) cement: mineral powder: quicklime: sodium silicate was 38:42:9.7:6.5. The flowability and strength of the fluidized solidified sludge using CCM were better than those using only cement. The hydration products of CCM solidified sludge mainly include hydrated calcium silicate gel and ettringite. The hydration products encapsulate soil particles and fill pores, significantly improving the strength of fluid solidified sludge. The strength improvement of CCM solidified sludge includes hydration, alkali induced volcanic ash reaction, ion exchange, micro expansion and filling effects.

TU472

重庆英才创新创业示范团队项目（cstc2024ycjh-bgzxm0012）；中央高校基本科研业务费资助项目（2023CDJKYJH105）；上海市政工程设计研究总院（集团）有限公司科学研究项目（K2023K124A）；重庆市建设科技计划项目