Experimental Investigation of Desiccation Cracking of Jilin Ball Clay Under Wet–Dry Cycles

Jilin ball clay is commonly employed as a construction material for the cover layer of landfills. The differences in temperature between the outside and inside of landfill renders the internal structure and stability of cover layer susceptible to desiccation cracks. To examine this phenomenon, a series of wet–dry cyclic tests were conducted employing the digital image correlation technique. The investigation systematically explored various crack characteristics of Jilin ball clay, including cracking morphology, water evaporation rate, and crack development under different thicknesses and temperature conditions. The findings of the test demonstrate that elevated temperatures have a positive correlation with the acceleration of specimen evaporation rates, and augmenting the thickness of the specimen can effectively impede crack formation due to the compensatory effect of moisture migration on surface water loss. Furthermore, the maximum values of crack length are attained prior to the inflection point of the desiccation curve during each cycle, and this trend becomes more pronounced as the temperature increases. However, the regularities in the pattern of changes in the average width of cracks were comparatively weaker when influenced by variations in thickness and temperature. The impact of wet–dry cycles on cracking parameters was primarily concentrated on the initial and subsequent cycles. The test results provide reference values for the subsequent research of drying-induced crack growth in Jilin ball clay.