Molecular dynamics data for modelling the microstructural behaviour of compacted sodium bentonites

Abstract The water retention curve deduced with low water content data allows the modelling of the bentonite void ratio associated with the pores located inside the clay aggregates, or micropores. However, if both the water content and the microporosity continue to increase, the latter can no longer be directly obtained from the former, because, in that case, the presence of water in the pores existing between the aggregates (macropores) may not be negligible. Therefore, it is not easy to obtain experimental evidence that allows to contrast whether the model's extrapolation of the microstructural void ratio obtained under dry conditions is valid for higher water contents. This work analyses the use of data obtained from molecular dynamics models to assess the validity of such extrapolations, and defines the variables needed to compare the results from molecular dynamics and laboratory experiments. The encouraging agreement obtained contributed to the confidence in the proposed procedure, which enabled a new strategy that uses molecular dynamics data to model the macroscopic behaviour of compacted sodium bentonites.