Flexural and Cracking Behavior of Clay Plates under Bending: Insights from Novel Tests and New Suction Parameters

This study investigates the flexural and cracking behavior of clay plates under pure bending conditions through a novel experimental framework. The test methodology overcomes limitations of traditional beam flexure and burst tests by employing an inflatable membrane to apply a uniform bending pressure while continuously supporting self-weight of the specimen. Kaolin clay plates of varying thicknesses were prepared by slurry consolidation and subjected to bending tests in an instrumented assembly. The bending stresses and moments, pore water pressures, and displacement of the surface were measured with conventional sensors. Additionally, the deformations of the specimens were captured with a three-dimensional scanner to evaluate the curvature and cracking patterns. Beyond the innovative experimental setup, this study also sheds light into the suction regime in clays subjected to flexure and sets forth novel pore water pressure parameters, which correlate well with the cracking tendencies of the clay material. A distinct curvature threshold is defined, and it is observed that the clay material’s crack opening tendencies are influenced by the suction regime in the specimen. Beyond the novel insights offered in this study, the normalized bending resistances yielded from the tests correlate well with existing research.