以矿渣和脱硫石膏为前驱体的高流态复合碱激发材料（high-fluidity slag and desulfurization gypsum composite alkali activated material, HSD-AAM）是目前构筑物修复与加固工程中常用的新型建筑材料之一。为了保证流动性，HSD-AAM通常采用较高的水胶比，影响了其早期强度，从而限制了HSD-AAM的应用。针对这一问题，通过室内试验研究了纳米二氧化硅（nanosilica, NS）掺量对HSD-AAM凝结时间、流动性、抗折和抗压强度（1、3、7 d）的影响，以期在不影响HSD-AAM流动性的前提下提升其早期强度；进而，通过扫描电子显微镜（scanning electronic microscopy, SEM）、X射线衍射（X-ray diffraction, XRD）和热重-差示扫描量热仪（thermogravimetric analysis and differential scanning calorimetry, TG-DSC）等方法分析了不同类型HSD-AAM的水化产物和微观结构，揭示了NS掺量对HSD-AAM早期强度的增强机理。结果表明：随着NS掺量的增加，HSD-AAM流动性降低且凝结时间缩短，而早期强度明显提升。NS掺量在0 ~ 3%之间时，每提升1%，HSD-AAM流动性平均降低6.0%；初凝和终凝时间平均缩短13.7%和10.0%；1 d抗折强度和抗压强度平均提升10.7%和20.2%；3 d抗折强度和抗压强度平均提升23.3%和12.4%；7 d抗折强度和抗压强度平均提升11.1%和32.9%。这是由于NS具有较高的火山灰活性，在早期与浆体内的Ca（OH）₂发生水化反应，促进其水化进程，生成大量的C-S-H凝胶，改善了浆体结构疏松的特点，使浆体早期微观结构更加致密。

The high-fluidity slag and desulphurization gypsum composite alkali material with (HSD-AAM) as precursors is one of the new building materials commonly used in the restoration and reinforcement of structures. In order to ensure fluidity, HSD-AAM usually uses a high water-binder ratio, which affects its early strength and thus limits the application of HSD-AAM. To solve this problem, the impact of the amount of nano-silica (NS) on the fluidity, setting time, flexural strength and compressive strength (1d, 3d, 7d) of HSD-AAM were studied through laboratory experiments, in order to improve the early strength of HSD-AAM without affecting its fluidity; Furthermore, thermogravimetric analysis and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electronic microscopy (SEM) were used to examine the hydration products and microstructure of the various varieties of HSD-AAM, the mechanism of enhancing the early strength of HSD-AAM by NS content was revealed. The results show that with the increase of NS content, the fluidity and setting time of HSD-AAM decrease, while the early strength increase significantly. When NS content is between 0 and 3%, the fluidity of HSD-AAM decreases by an average of 6.0% with each increase of 1%; the initial and final setting times shorten by 13.7% and 10.0% respectively; 1 d flexural strength and compressive strength increase by 10.7% and 20.2% on average; 3 d flexural strength and compressive strength increase by 23.3% and 12.4% on average; 7 d flexural strength and compressive strength increase by 11.1% and 32.9% on average. This is due to the high pozzolash activity of NS and the hydration reaction with Ca(OH)₂ in the slurry in the early stage, which promotes the hydration process and generates a large amount of C-S-H gel, which improves the loose structure of the slurry and makes the microstructure of the slurry more dense in the early stage.