Chemo-mechanical aging and electrokinetic effects on silica-rich sands

Abstract

Sands aging significantly influences their shear strength through a combination of mechanical and chemical interactions. While the effects of mechanical aging — such as particle rearrangement and interlocking — are well understood, the contribution of chemical processes remains less explored. This study examines the coupled chemo-mechanical aging mechanisms that govern sand behavior. Through X-ray diffraction and zeta potential analysis, the influence of mineralogical composition and electrokinetic interactions under varying pH conditions is quantified. Unconfined compression tests indicate that electrochemical attraction, particularly in silica-rich environments, enhances compressive strength by up to 3 times over six months. Statistical validation confirms significant strength gains across different sand types, highlighting the role of alkali-silica reactions. This findings challenge conventional predictive models of long-term granular soil behavior, offering a new perspective for geotechnical applications influenced by time dependence.