Density of water adsorbed on bentonites: Determination and effect on microstructural void ratio modelling

The ability of helium gas displacement pycnometry to characterise the reduction adsorbed water density with increasing bentonite content was tested. For this purpose, after obtaining grain (which assumed be constant), an intensive campaign 45 experiments carried out two bentonites for a total 90 determinations, very consistent results. Furthermore, retention curve one fully characterised by 95 tests chilled-mirror dew-point psychrometer. results were used determine microstructural void ratio, both assuming constant and considering variation obtained pycnometer. It verified that value, lower (1 g/cm3) than experimental (values 1.20 g/cm3 under hygroscopic conditions), higher values ratios are predicted, up 15% greater relative humidity 70% (0.46 instead 0.40). humidities comparison loses its consistency, since presence capillary cannot disregarded, calculation ratio is based on assumption present in mainly form water. However, does not compromise analysis performed, as provide enough information demonstrate relevance errors can occur when deriving models without taking into account