Changes in the basic structure and strength deterioration of clay minerals with different hydration degrees

Abstract To investigate the influence of clay mineral microstructures on mechanical properties across varying hydration levels, this study employed molecular dynamics simulations to conduct uniaxial tensile strength tests in three orthogonal directions ( x , y , z ) using illite, montmorillonite and kaolinite. The moisture content was varied from 0% to 10% in 1% increments and from 0% to 50% in 10% increments. The observations highlight the role of water molecules in disrupting the inherent microscopic atomic structure of clay minerals, leading to diminished stability and a decline in tensile strength. As moisture content increased, there was a pronounced increase in the layer spacing of all three clay minerals, indicative of their hydration expansion behaviour. Concurrently, discernible reductions in both the tensile strength and Young's modulus of the clay minerals were observed.