Study on the Erosion Mechanism of the Solidified Silt Under Sulphate–Chloride Erosion

• Published in: Geotechnical and geological engineering Vol. 40; no. 7; pp. 3749 - 3762
• Main Authors: Wu, Yankai, Zhu, Jiayi, Shi, Kejian, Qiao, Xiaolong, Yu, Xinbao, Zhang, Mingfei
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.07.2022; Springer Nature B.V
• Subjects: Cement; Chloride; Chloride ions; Chlorides; Civil Engineering; Compressibility; Compressive strength; Concrete; Earth and Environmental Science; Earth Sciences; Erosion mechanisms; Erosion rates; Erosion resistance; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Ions; Mechanical properties; Metal powders; Microstructure; Moisture content; Moisture effects; Original Paper; Permeability; Physical properties; Powder; Silt; Slag; Soil; Soil analysis; Soil compressibility; Soil erosion; Soil improvement; Soil mechanics; Soil moisture; Soil permeability; Soil properties; Soils; Steel; Sulfates; Terrestrial Pollution; Void ratio; Waste Management/Waste Technology; Water compressibility; Water content; Corrosion mechanism; Steel slag powder; Solidified soil; Cement; Microstructure; Sulfate–chloride; Unconfined compressive strength; Erosion
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-022-02123-8

Silt and mucky soil have high natural moisture content, poor water permeability, high compressibility, low strength, and a large void ratio. Silt and mucky soil solidify by adding cement in practical projects. In this work, the erosion characteristics of the silt and mucky soil have improved by adding steel slag powder to it. This paper compared the mechanical properties of the solidified soil with that of the pure cement-solidified sludgy soil under the same erosion environment. The physical properties and the erosion mechanism of the solidified soil were analyzed in macroscopic and microscopic aspects. Our findings show that the strength range of the solidified soil sample mixed with steel slag powder is 0.028, and the strength change range of the sample mixed with cement soil is 0.062. It can see that the steel slag powder and its hydration products have effectively improved resistance to ions erosion of the solidified soil. When chloride ions and sulfate ions coexist in the erosion solution, chloride ions can delay the erosion rate of sulfate ions on the solidified soil and improve the compressive strength of the solidified soil. The higher the chloride ions concentration, the more pronounced the effect. As the concentration of SO 4 2− :Cl − increased from 3:1 to 1:3 during the same erosion time, solidified soil mass change rate increased by 0.8%. Finally, SEM images were used to analyze the microstructure changes of the solidified soil with Sulfate–chloride mixed solution and discussed the erosion and damage mechanism of solidified soil.