## 7 Conclusions  
In this study, the feasibility and curing mechanism of synergistic industrial waste-cement was analyzed by taking sea-phase silty soil as the research object, and an orthogonally designed test was used to improve the soft soil in an indoor environment, utilizing cement and a variety of industrial wastes. We drew the following conclusions:  
(1) The orthogonal test results show that the cement dosage had the most significant effect on the compressive strength of the cured soil, and the blast furnace slag in the industrial waste also played a major role. The phosphogypsum dosage had a greater effect than the fly ash dosage at 3d and 28d, and the dosage of fly ash was greater than that of phosphogypsum at 7d. Through the analysis of the 3d, 7d, and 28d compressive strength, we found that the best ratio for the cement-industrial slag curing agent for early strength was 1:0.4:0.4:0.05 (cement-fly ash-slag-phosphogypsum), and the best ratio for late strength was 1:0.1:0.4:0.05, which saved 49% and 38% cement year on year. (2) An increase in the initial moisture content caused a rapid decrease in the strength of the fluid-consolidated soils, but liquidity was substantially improved. There was a loss of pumpability in the cured soils when the initial moisture content was less than 180 percent. When the water content was reduced to 140%, the strength of Ratios I and II reached 550 kPa and 586 kPa, respectively, and the fluid-cured soil specification strength criteria were sufficiently met. (3) There was a critical dosage of 6% for the polycarboxylic acid water-reducing agent, and when the dosage was greater than this, the flow rate changed significantly. With curing agent Ratios I and II, the flow rate slowly increased when the water-reducing agent dosage exceeded 6%. The water-reducing agent had a significant effect on the mobility of the cured  
Figure 10: Microstructural images of flowable stabilized soil. (**a**) Seven-day curing of pure cement. (**b**) Twenty-eight-day curing of pure cement. (**c**) Twenty-eight-day curing of stabilizer Ratio I. (**d**) Twenty-eight-day curing of stabilizer Ratio I.  
soils. From 6% to 7% dosing, the flow values of the two formulations of the fluid-cured soil increased by 37.2% and 38.8%. Through the rational mixing of the water-reducing agent, the solidified soil's compressive strength was reduced by a small amount, while its mobility was significantly improved. (4) The right amount of calcium chloride could effectively improve the early strength of the cured soil. From the experimental data, it is observed that the compressive strength of the soil increased and then decreased with the increase in the calcium chloride content. Additionally, the strength of the cured soil peaked at a 1.5% calcium chloride dosage. The calcium chloride produced by the reaction further reacted with the hydrated calcium aluminate to form the F's salt. Ultimately, the compressive strength of the cured soil was reduced. At the same time, an increase in the F's salt content could increase the flowability of the mix by a small amount. (5) Through microscopic analysis, it was shown that the cement-industrial waste reaction was synergistic, and the number of gel products, such as C-S-H, in the fluid-cured soil significantly increased. The resulting expanded hydrated AFt crystals filled the inter-pore spaces of the soil particles, and the interwoven formation of the skeleton through the products generated by the hydration of the cementitious material made the structure of the soil body denser and improved its mechanical properties. Conceptualization, D.W.; methodology, D.W. and H.Y. ; data curation, Y.S. All authors have read and agreed to the published version of the manuscript. This work was supported by the Youth Science Fund (A-class) of the Hunan Natural Science Foundation (2025 JJ20049) and Science Fund for Distinguished Young Scholars of Hubei Province (no. 2024 AFA051). Not applicable. The original contributions presented in this study are included in the article.