Local Moisture Content and Stress Distributions within Clay During Drying Shrinkage

Changes of local moisture content and stress during drying are calculated by considering both osmotic suction pressure and stress gradients as the effective driving force of moisture transfer by use of the finite-element method. Calculated local moisture content shows good agreement with experimental values. Relatively large tensile stress at the surface of drying stock and compressive stress in the stock are obtained under high-speed drying conditions. Calculated results show the occurrence of tensile stress in the material under certain conditions. Stress in the mixed clay seems to be smaller in value than in Kibushi clay, and from this result, possibility of avoidance of cracking may be confirmed by adding a small amount of glass beads, even under high-speed drying conditions.