Effect of Freezing, Drainage Distance, and Radial Location on the Specific Surface Area of Kaolinite Clay

This study investigates the influence of freezing, drainage proximity, and radial location on the specific surface area (SSA) of consolidated kaolinite clay (Edgar Plastic Kaolin). In cold regions, freezing can alter the microstructure of fine-grained soils, potentially affecting key engineering properties such as permeability, strength, and compressibility. To examine these effects, two clay specimens were consolidated under identical effective stress (600 kPa) in a temperature-controlled triaxial system. Following consolidation, one specimen was maintained at 20°C, while the other was frozen at −5°C. Each specimen was then sectioned into top, middle, and bottom discs, and gas adsorption tests were conducted at five radial locations per disc to evaluate SSA and pore structure. Results showed no significant difference in SSA between frozen and unfrozen specimens, suggesting that −5°C was not sufficient to alter the microstructure at the scale detectable by the used analysis. However, a slight broadening of the hysteresis loop in the frozen specimen indicates subtle changes in larger pore connectivity.