Stiffness characteristics of soluble mixtures

Soils naturally contain grains of different minerals, which may be dissolved under chemical or physical processes. The dissolution leads to changes in the microstructure of the particulate media, such as an increase in local voids or permeability, which affects the strength and deformation of soils. This study focuses on the small strain stiffness characteristics of soluble mixtures, which consist of sand and salt particles at different volume fractions. Experiments were carried out in a conventional oedometer cell integrated with bender elements for the measurement of shear waves. Dissolutions of particles were implemented by saturating the mixtures at various confining stresses. Experimental results show that, after dissolution, the vertical strain and the void ratio increase, whereas the shear wave velocity decreases. The decrease of the velocity results from the void ratio increase and particle contact decrease. It is proven that specimens prepared from sand and salt particles are able to provide valuable insight into the macrostructural behaviour of soluble mixtures.