One of the methods used to improve the physical and mechanical properties of problematic soils is chemical stabilization. This study appraises the eventuality of using seashell ash (SSA), to enhance engineering properties of the fat clay. For this purpose, samples were prepared at five different contents of SSA (i.e., 0, 3, 6, 9, and 12% by dry weight of the soil) and four various curing periods (i.e., 1, 7, 14, and 28 days). Compaction, unconfined compressive strength (UCS), and unconsolidated-undrained triaxial tests, X-ray fluorescene, and scanning electron microscopy analyses were performed to determine the compaction characteristics, compressive strength and durability, shear strength parameters, and mineralogical and microstructural variations in stabilized samples. Based on the results and considering the energy-saving and time, it was recognized that the appropriate time and temperature for the incineration of SSA in this study were set to 1 h and 900 °C, respectively. Results showed that SSA can considerably enhance the strength and durability of the fat clay. The highest UCS enhancement is obtained with 9% SSA and then decreased. Furthermore, with increasing moisture content, the UCS increased in the SSA-stabilized samples, unlike in the case of unstabilized clay. The shear strength parameters increase with increasing SSA contents. Microstructural analyses indicated that the addition of SSA had a major impact on the structure of stabilized samples. Adding SSA by covering the particles and filling the pores between them causes a stiffer and denser structure. Finally, the results of this study corroborate the effectiveness of SSA as a nontraditional additive for soil stabilization.

用于改善有问题土壤的物理和机械性能的方法之一是化学稳定。本研究评估了使用贝壳灰 (SSA) 来增强脂肪粘土的工程特性的可能性。为此，制备了五种不同含量的 SSA（即土壤干重的 0、3、6、9 和 12%）和四种不同的固化期（即 1、7、14 和 28天）。进行压实、无侧限抗压强度 (UCS) 和松散-不排水三轴试验、X 射线荧光和扫描电子显微镜分析，以确定稳定的压实特性、抗压强度和耐久性、剪切强度参数以及矿物学和微观结构变化样品。根据结果​​并考虑节能和时间，认识到本研究中 SSA 焚烧的适当时间和温度分别设定为 1 小时和 900 ℃。结果表明，SSA 可以显着提高脂肪粘土的强度和耐久性。最高的 UCS 增强在 9% SSA 时获得，然后降低。此外，随着水分含量的增加，SSA 稳定样品中的 UCS 增加，这与不稳定粘土的情况不同。剪切强度参数随着 SSA 含量的增加而增加。微观结构分析表明，添加 SSA 对稳定样品的结构有重大影响。通过覆盖颗粒并填充它们之间的孔隙来添加 SSA 会导致结构更硬、更致密。最后，