Theoretical and experimental analysis of stresses and fractures in clay like materials during drying

A risk of clay fracture during drying is analysed theoretically and experimentally. The distribution and evolution of stresses in clay samples of cylindrical form are described with the help of viscoelastic Maxwell model. The theoretical curves of stress distribution and evolution are compared with experimental data presenting the time evolution of crack events and the amount of fracture energy released during drying at different drying conditions. These two experimental descriptors are monitored with the help of acoustic emission method (AE) on the cylindrical clay samples dried in the laboratory drier. The analysis proves that the number of AE events and the energy of AE events may serve for identification of fracture intensity occurring in materials during drying.