Freeze-Thaw Damage Characterization of Cement-Stabilized Crushed Stone Base with Skeleton Dense Gradation.

The skeleton dense graded cement-stabilized crushed stone base is a widely used material for road construction. However, this material is susceptible to freeze-thaw damage, which can lead to degradation and failure, for which there is still a lack of an in-depth understanding of the freeze-thaw damage characteristics. This study aims to assess the mechanical performance and the freeze-thaw damage characteristics of the cement-stabilized crushed stone base with skeleton dense gradation based on a mechanical test and acoustic technology in a laboratory. There is a gradually increasing trend in the mass loss rate of the base material with an increase in freeze-thaw cycles. The curve steepens significantly after 15 cycles, following a parabola-fitting pattern relationship. The compressive strength of the cement-stabilized crushed stone base also decreased with a parabola-fitting pattern, and the decrease rate may accelerate as the freeze-thaw cycles increase. The resilience modulus of the base material decreased with increasing freeze-thaw cycles, following a parabolic trend. This suggests that the material's resistance to freeze-thaw damage decreases with increasing cycles. The ultrasonic wave velocity decreased with increasing freeze-thaw cycles, exhibiting a parabolic trend. This decline can be attributed to microcracks and defects developing within the material, offering insights for monitoring and predicting its service life. The damage progression of the cement-stabilized crushed stone base was found to occur in three stages: initial, stationary, and failure. The duration of stage I increased with freeze-thaw cycles, while the duration of stage III decreased. The findings provide valuable insights into the mechanisms and processes of freeze-thaw damage in a cement-stabilized crushed stone base with skeleton dense gradation.