## 3 Results and Discussion
### Discussion of Orthogonal Experimental Results
#### 3.1.3 Effect of Factors on the Activity of Composite Micronized Powder  
As can be seen from Table 5, the major and minor laws of the effect of each factor on 7 d activity index were B \(>\) D \(>\) A \(>\) C, and the major and minor laws of the effect of each factor on 28 d activity index were B \(>\) D \(>\) C \(>\) A. Figure 3 shows the effect curves of each factor on the mortar test blocks at different ages. Combined with Figure 3 and Table 5, it can be seen that the 7 d activity index increases first and then decreases with the increase in BFS, MTS and GA doping, increasing with the amount of DG doping. When the ratio is A3B3C3D4, the 7 d activity index of composite micronized powder is the highest. The 28 d \begin{table}
\begin{tabular}{c c c c c c} \hline
**Grade** & **Q-I** & **Q-II** & **Q-III** & **Q-IV** & **Q-V** \\ \hline Electric flux (C) & QS \(\geq\) 4000 & 2000 \(\leq\) QS \(<\) 4000 & 1000 \(\leq\) QS \(<\) 2000 & 500 \(\leq\) QS \(<\) 1000 & QS \(<\) 500 \\ \hline \end{tabular}
\end{table} 
Table 6: Grading of concrete resistance to chloride ion penetration (electric flux method). Figure 2: Curves of the effect of each factor on the substrate electric flux. activity index increases with the increase in BFS and GA, decreases with the increase in MTS and with an increase in the amount of DG, it increases first and then decreases. When the ratio is A4B4C4D2, it has the highest 28 d activity index, i.e., 35% BFS, 30% MTS, 0.3% GA, 5% DG and 30% WQMS. BFS, MTS and WQMS represent the main active materials of the composite micronized powder, among which BFS is a granular active material with calcium silicate and calcium aluminate as the main components. It is discharged from iron-making and formed by water-quenching and rapid cooling treatment, generally containing 80-90% in a glassy state, in a sub-stable state, with high reactivity, and is a potential water-hardened gelling material [25]. Although the main chemical composition of MTS and WQMS and their relative amount are similar to BFS, the glass body occupies most of it but is lower than that in BFS. As a result, its activity is lower. However, the aqueous solution of MTS is weakly acidic, which can adjust the PH value in the gel system to have an effect on hydration. Moreover, its fluctuation of admixture has a greater effect on the activity of composite micronized powder. The phenomenon in the experiment shows that the activity index of composite micronized powder increases with the BFS and MTS doping in a certain range, and the MTS doping is the most significant factor affecting the composite micronized powder activity index among the four factors. However, because the total amount of composite micronized powder is fixed, excessive amounts of both substances will lead to reduced dosing of DG, which reduces the effect of early DG on the alkaline excitation of mineral powder, thus the 7-d activity decreases when excessive amounts of both are dosed. The reason why the 7 d activity of composite micronized powder increases with a certain range of DG admixture is that the gypsum dihydrate in DG can promote the hydration of C3S in cement clinker, while the presence of its soluble impurity ions and CaCO\({}_{3}\) is conducive to accelerating the hydration of cement, which increases the concentration of Ca(OH)\({}_{2}\) in the liquid phase compared with the hydration system without DG, providing conditions for the alkaline excitation of BFS powder and prompting the hydration reaction of BFS powder. On the other hand, the DG in the system can react directly with the active Al\({}_{2}\)O\({}_{3}\) in the BFS powder in an alkaline environment to form calcium alumina, which has an alkaline excitation effect on the BFS powder, thus contributing to the early strength of the system [26].