At the Representative Elementary Volume scale, during axisymmetric stress state conditions on clayey soils, two mechanisms related to the two components of stress tensor play a role in the evolution of the volumetric strains. The variation of the isotropic part of the stress tensor induces positive volumetric strain, obtained in form of contraction; the deviatoric part variation induces volumetric strain that can be positive (contraction) and/or negative (dilatancy) depending on the stress paths direction, and on the loading history (Hattab and Hicher, 2004). Starting from this framework of the behavior in clayey media, the goal here is to try to identify, experimentally, the local (micro) mechanisms that can be related to the volumetric strain variations. The experimental approach consisted first to identify the macro behavior, then the local microstructure variations related to a stress level and a mechanical loading path. Microscopic investigations on the initially saturated remoulded clays, normally or overconsolidated, are possible using different complementary techniques such as: the scanning electron microscopy (SEM) with an appropriate method of image processing analysis- the method allowing to capture the particles organization states and the pores properties- X-ray microtomography (XR-μCT) allowing to capture the eventual local cracks at the mesoscale (as shown in Gao and al. 2020), or FIB-SEM technique allowing a 3D visualization and the investigation of the clay fabric organization (Ding et al. 2024). Recent works demonstrate on the other hand how the interactions of clay particles with their environment, can first participate in fabric structuring of the clayey soils during the sedimentation process. and what could be the consequence on their mechanical behavior especially at low stress domain.