THE EFFECT OF MECHANICAL LOADING AND CARBONATION ON THE PHYSICAL PROPERTIES OF SOLIDIFIED SAND

ABSTRACT: Information on the long-term performances of the stabilization/solidification (S/S) technique under real field conditions remains sparse. In this study, a modified triaxial cell was developed to evaluate the physical properties of silica sand solidified with cement. The modified triaxial cell was required to study the influence of loading and carbonation under a confining stress simulating field conditions. The permeability and compressive strength were measured at different stages of four main scenarios involving carbonation only, axial loading only, carbonation first then loading, and loading first then carbonation. The influence of external loading and carbonation on the physical properties of solidified sand is complex. It involves creating new voids (fractures) that increase the permeability, lower the shear strength, and channel the water flow. It also involves calcite precipitation that fills the pore space with opposite effects on the mechanical and hydrodynamic properties of the solidified sand. Results indicate that the mechanical loading accelerated the damage to the S/S samples and increased their permeability. Deterioration owing to loading decreased in the presence of carbon dioxide. The results of this ongoing study will help to understand the long-term performances of the S/S technique.