Quicklime is widely utilized in stabilizing special soils, and the curing condition, as well as freeze-thaw cycles (FTCs), can significantly affect the engineering properties of lime-stabilized soil. In this study, quicklime is adopted to stabilize the saline soil in cold regions. The effects of curing time, numbers of freeze-thaw cycles, and constraint conditions (three-dimensional constraint, radial constraint, and no constraint) on mechanical and microstructure characteristics are investigated by performing a series of unconfined compression tests (UCT), X-ray diffraction (XRD) and scanning electron microscope (SEM) tests. The UCT results indicate that specimens obtain the highest unconfined compression strength (UCS) under three-dimensional constraint and the lowest UCSs under no constraint. XRD and SEM tests reveal that pozzolanic reaction and carbonation play an important role during curing. UCSs of specimens cured for 7 days increase with the increase of FTCs while those of specimens cured for 28 days decrease in the early stage of FTCs but increase after 10 FTCs. FTCs destroy the original structure of stabilized soil and break the aggregates. Small particles of free quicklime and broken aggregates fill the pores. In addition, cementitious materials bond these particles together which resulted in a denser microstructure and an increase of UCS after 10 FTCs.

生石灰广泛用于稳定特殊土壤，其养护条件以及冻融循环 (FTC) 会显着影响石灰稳定土的工程特性。本研究采用生石灰来稳定寒冷地区的盐渍土。通过执行一系列无侧限压缩试验（UCT），研究了固化时间、冻融循环次数和约束条件（三维约束、径向约束和无约束）对机械和微观结构特性的影响，X-射线衍射（XRD）和扫描电子显微镜（SEM）测试。UCT结果表明，试件在三维约束下获得最高的无侧限抗压强度（UCS），在无约束条件下获得最低的UCS。XRD和SEM测试表明，火山灰反应和碳酸化在固化过程中起重要作用。治愈7 d标本的UCSs随着FTCs的增加而增加，而治愈28 d标本的UCSs在FTCs早期减少，但在FTCs 10后增加。FTC 破坏稳定土壤的原始结构并破坏聚集体。游离生石灰的小颗粒和破碎的聚集体充满孔隙。此外，胶凝材料将这些颗粒粘合在一起，导致微观结构更致密，并且在 10 次 FTC 后 UCS 增加。FTC 破坏稳定土壤的原始结构并破坏聚集体。游离生石灰的小颗粒和破碎的聚集体充满孔隙。此外，胶凝材料将这些颗粒粘合在一起，导致微观结构更致密，并且在 10 次 FTC 后 UCS 增加。FTC 破坏稳定土壤的原始结构并破坏聚集体。游离生石灰的小颗粒和破碎的聚集体充满孔隙。此外，胶凝材料将这些颗粒粘合在一起，导致微观结构更致密，并且在 10 次 FTC 后 UCS 增加。