On the mechanism for desiccation cracks initiation in clayey materials

Our contribution investigates the mechanism of desiccation crack initiation and makes an attempt to model the onset of cracking in simple clay forms exposed to desaturation by air drying. Constrained drying laboratory tests are first performed on initially saturated clay forms in a temperature and relative humidity controlled environment. Displacement field and crack formation in proximity of the evaporating surface are monitored using high definition cameras. Cracking is tentatively modelled using a coupled hydro-mechanical model based on the assumption that cracking is associated with failure in shear according to recent findings in literature. The comparison of numerical simulations with experimental results made it possible to assess the assumption that cracking occurs due to failure in shearing.