Enhancing the mechanical performance of cement-stabilized macadam considering low-compaction and cold environment

Cement-stabilized macadam (CSM) at pavement edges is prone to segregation and insufficient compaction, and its deterioration is intensified by freeze–thaw action in cold regions. This study investigated the mechanical performance of CSM under simulated cold-climate construction and service conditions. Specimens with different compaction degrees, cement contents, grout flowabilities, curing regimes, freeze–thaw cycles and moisture conditions were tested for strength and compressive resilient modulus. CT, SEM and XRD examined microstructural evolution. Results show that higher compaction and cement content reduced porosity and improved strength by promoting AFt and C-S-H formation. High-flowability grout provided deeper reinforcement, whereas low-flowability grout mainly densified surface layers. Low-temperature and low-humidity curing weakened the interfacial transition zone, and freeze–thaw cycles, especially under long-term immersion, caused microcracking and strength loss. Regression and Pearson analyses identified compaction, grout treatment and curing regime as key factors.