<p>Chemical stabilization via hydration reactions with cement or lime is a universally applied method to improve the mechanical properties of shallow foundation materials (e.g., subgrade or subbase support). Accelerated mineral carbonation is an emerging stabilization pathway intended to bypass conventional hydration reactions by deliberately introducing carbon dioxide in high concentrations to generate a carbonate binder. Reacted carbon dioxide gas is permanently sequestered in the binder, and thus soil carbonation has the potential to substantially reduce carbon emissions associated with production of additives like lime and cement. This study examines the durability of highly frost-susceptible non-plastic silt carbonated with lime in a large soil box. The silt was exposed to soaking and multiple freeze–thaw cycles in an environmental chamber. Subsurface temperatures, deformations, and shear wave velocities were continuously monitored during freeze–thaw cycling. The California bearing ratio (CBR), moisture contents, and carbonate contents were also measured to assess changes throughout the experiment. The experimental design successfully simulated a 1D (top-down) freezing front and two thaw fronts typically observed in the field, and the carbonated silt proved durable based on measured shear wave velocities and CBR values that remained significantly elevated relative to uncarbonated material. After a 12-week drying period, CBR values recovered or exceeded levels observed before soaking and freeze–thaw cycling, further demonstrating the resilience of the carbonated silt to harsh environmental conditions.</p>