# Study on Strength and Microstructure of Red Clay Reinforced by F1 Ionic Soil Stabilizer
## 6 Conclusions  
The basic physical parameters, shear strength parameters, and the change regulation of the micropore structure of red clay reinforced with F1 ionic soil stabilizer were studied through the basic physical parameter test UU test, freeze-thaw cycle test, and SEM image analysis. The following conclusions were drawn.  
1. With the increase of F1 content, the plastic limit, permeability coefficient, optimum moisture content, and maximum dry density of solidified red clay first increased and then decreased, and the liquid limit and plasticity index first decreased and then increased, indicating that F1 can significantly improve the water sensitivity and compaction characteristics of red clay.
2. With the increase of F1 content, the maximum deviator stress, cohesion, and internal friction angle of F1 reinforced red clay show a change regulation of first increasing and then decreasing, and 0.5 L/m\({}^{3}\) was the best F1 dose. Compared with undisturbed red clay, the cohesion and internal friction angle of the red clay strengthened with the optimal dosage increased by 1.64 times and 1.30 times, respectively, indicating that F1 can significantly increase the shear strength of the red clay.
3. The shear strength parameters of F1 reinforced red clay decreased with successive freeze-thaw cycles. Compared with undisturbed red clay, the cohesion and internal friction angle of solidified red clay were 18.4% and 57.1% higher, respectively, with the optimal dosage of F1 0.5 L/m\({}^{3}\) after 15 freeze-thaw cycles, indicating that F1 can still significantly increase the strength of red clay after 15 freeze-thaw cycles.
4. The pore area ratio, average Feret diameter, and fractal dimension of red clay exhibited a change regulation of first decreasing and then increasing with increased F1 content. Compared to undisturbed red clay, the pore area ratio, average Feret diameter, and fractal dimension of the reinforced red clay with the optimal F1 content of 0.5 L/m\({}^{3}\) were reduced by 56.64%, 32.27%, and 2.43%, respectively, indicating that the pore size and area of the red clay after F1 reinforcement were significantly reduced, and the pore morphology tended to be regular.  
Conceptualization, [PERSON] ([PERSON]) and J.-d.L.; methodology, J.-d.L.; software, [PERSON] ([PERSON]); validation, J.-d.L., Y.Z. and G.Z.; formal analysis, [PERSON] ([PERSON]); investigation, D.J.; resources, [PERSON] ([PERSON]); data curation, J.-d.L.; writing--original draft preparation, [PERSON] ([PERSON]); writing--review and editing, [PERSON] ([PERSON]) and J.-d.L.; supervision, [PERSON] ([PERSON]); project administration, [PERSON] ([PERSON]); funding acquisition, Y.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China grant number 51868038 and 52268058, project supported by the Young Scholars Science Foundation of Lanzhou Jiaotong University grant number 2022054 and Gansu Province Youth Science and Technology Fund Program grant number 22J8F8 RA369.  
This study did not involve humans or animals.  
This study did not involve humans.  
This study did not report any data.  
The authors declare no conflict of interest.