Plane axisymmetric modelling of open granular bentonite mixtures

A new contact model is proposed to improve the simulation of the hydration of granular bentonite mixtures. When these mixtures are abstracted as a discrete set of continuous systems in contact, excessively low predictions of swelling pressures are obtained when simulating the early stages of hydration using a plane axisymmetric approximation. This is especially true for relatively open structured mixtures with an average dry density less than 1.5 Mg/m3. The proposed contact model has allowed improved predictions while maintaining the axisymmetric analysis in the demanding inspection tests analysed. Hence, it is an interesting tool to simulate the whole homogenisation process of open granular bentonite mixtures. However, it is necessary to intensify its validation by analysing new experimental evidence, and to evaluate its development, because given its simplicity it presents some difficulties to reproduce the collapse of the megapores when hydration progresses.