Cement-solidified soil (CSS) is a prevalent ground-improvement technique for weak foundations in seasonally frozen regions, where bending failure constitutes a principal failure mode. This study investigated the effects of moisture content and freeze-thaw cycles on flexural fracture behavior of silty clay CSS (SC-CSS) and sandy soil CSS (SS-CSS) through three-point bending tests. The results indicate that SC-CSS exhibits linearly decreasing peak fracture loads with rising moisture content and freeze-thaw cycles, while SS-CSS exhibits a quadratic reduction trend. Both materials display increased fracture angles and surface roughness under these conditions. This enhanced roughness manifests as groove-dominated morphologies in SC-CSS, contrasting with the localized columnar protrusions and pits observed in SS-CSS. Higher moisture content amplifies freezing-induced volumetric expansion, which increasing interparticle distances, degrading cementation bonds, and reducing strength parameters. More freeze-thaw cycles intensify particle fragmentation and porosity, further diminishing mechanical performance. These findings provide valuable insights for optimizing CSS reinforcement strategies for tunnels, deep foundations, and underground structures in seasonally frozen environments.
Wei et al. (Mon,) studied this question.