## 3 Research on Alkali-Activated Grout Materials
### Study on UCS and Fluidity of Alkali-Activated Composite Grouting Material
#### 3.2.2 Results and Analysis of Alkali-Activated Composites Grouting Material Fluidity Test  
Fluidity is a crucial indicator for grouting materials used in karst cave treatments, directly affecting their pumpability, injection efficiency, and quality. High fluidity materials can pass through pumping systems more smoothly, filling voids and cracks, enhancing reinforcement effects, and reducing resistance and wear during the pumping process, thereby extending equipment lifespan. Therefore, when selecting and preparing grouting materials, their fluidity should be thoroughly considered. This can be achieved by adjusting the water-cement ratio and additives to meet project requirements, and by conducting comprehensive indoor tests to evaluate their fluidity.  
To ensure that the fluidity of the alkali-activated composite-stabilized soil in this experiment meets grouting requirements, the \"Test Method for Fluidity of Cement Mortar\" (GB/T 2419-2005) [44] was referenced to test the fluidity of the designed alkali-activated composite-stabilized soil. According to the \"Construction Plan for Karst Treatment in the Low-White Section of Work Area 2 of the Phase IV Project of Shenzhen Urban Rail Transit Line 3\", the fluidity of grouting materials is classified as either qualified or unqualified based on the fluidity test. The qualified fluidity range is 190-220 mm, while unqualified fluidity is either greater than 220 mm or less than 190 mm. The results of the fluidity test for the alkali-activated composite grouting material are shown in Table 7.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Test Number** & **Soil-to-Binder Ratio** & **Slaked Lime Content** & **Water-to-Solid Ratio** \\ \hline D-1 & 8:2 & 0.0\% & 0.26 \\ D-2 & 8:2 & 1.5\% & 0.28 \\ D-3 & 8:2 & 3.0\% & 0.30 \\ D-4 & 8:2 & 4.5\% & 0.32 \\ D-5 & 7:3 & 0.0\% & 0.28 \\ D-6 & 7:3 & 1.5\% & 0.26 \\ D-7 & 7:3 & 3.0\% & 0.32 \\ D-8 & 7:3 & 4.5\% & 0.30 \\ D-9 & 6:4 & 0.0\% & 0.30 \\ D-10 & 6:4 & 1.5\% & 0.32 \\ D-11 & 6:4 & 3.0\% & 0.26 \\ D-12 & 6:4 & 4.5\% & 0.28 \\ D-13 & 5:5 & 0.0\% & 0.32 \\ D-14 & 5:5 & 1.5\% & 0.30 \\ D-15 & 5:5 & 3.0\% & 0.28 \\ D-16 & 5:5 & 4.5\% & 0.26 \\ \hline \end{tabular} Note: The soil-to-binder ratio in the table is the mass ratio of the in situ soil to the ground aggregate; the slaked lime content is the mass ratio of the slaked lime to the ground aggregate; and the water-to-solid ratio is the ratio of the sum of the masses of the water in the mixing water and the alkali stimulant to the total mass of the solids.  
\end{table}
Table 6: Alkali-activated grout materials orthogonal test.  
According to the results of the fluidity test, within the scope of this experimental study, when the soil-to-binder ratio is less than 8:2, the fluidity of the alkali-activated composites growing material meets the specific construction requirements. Table 8 and Figure 7 present the range analysis and mean analysis results for the fluidity test of alkali-activated composite grouting material, respectively. The analyses of range and mean indicate that the primary factor affecting the fluidity of alkali-activated composite grouting material is the soil-to-binder ratio. As the soil-to-binder ratio decreases from 8:2 to 5:5, the fluidity also decreases. The most significant change in fluidity occurs when the soil-to-binder ratio increases from 7:3 to 8:2. The second factor influencing fluidity is the water-to-solid ratio, with fluidity increasing as the water-to-solid ratio rises within the scope of this experiment. The addition of slaked lime, used as an alkaline supplement, has minimal impact on the fluidity due to its low content.