Study on Physicochemical and Compressive Deformation Characteristics of Dispersive Clay under Freeze-Thaw and Soaking Conditions (Postprint)

Han Xiao 1, He Rui 1, Wang Lixiang 2,3

(1. PowerChina Guiyang Engineering Corporation Limited, Guiyang 550081, China; 2. Huangshan University, Huangshan 245021, China; 3. Anhui Province (Huaihe River Water Resources Science Research Institute, Anhui Hefei 233000)

(1. Guiyang Engineering Corporation Limited, Guiyang 550081, China; 2. Huangshan University, Huangshan 245021, China; 3. Anhui and Huaihe River Institute of Hydraulic Research, Hefei 233000, China)

Abstract

To investigate the effects of freeze-thaw cycles and soaking on the physicochemical properties, deformation characteristics, and state of dispersive clay, indoor physical and chemical tests as well as compression tests were conducted on dispersive clay. Based on the test results, a compression deformation formula for dispersive clay under freeze-thaw cycles and soaking conditions was proposed.

The results indicate that after undergoing freeze-thaw cycles and soaking, sodium and potassium ions in the clay decreased by 91% to 95%, and the pH value dropped from 9.24 to 7.47; particle sizes (0.075–0.005 mm and <0.005 mm) increased, liquid limit and specific gravity increased, while the plastic limit remained unchanged; soaking caused the exchange and loss of sodium ions in dispersive clay, resulting in higher compressibility compared to non-dispersive clay; freeze-thaw cycles and soaking deteriorated the dispersive clay structure, accelerated the ion loss process, altered the compression curve, and significantly deepened the flocculated structure. After approximately 10 hours of freeze-thaw cycles and soaking, the dispersive clay exhibited a completely flocculated structure.

Keywords: Dispersive clay; Freeze-thaw cycles; Exchangeable sodium; Physicochemical properties; Compressibility

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