Soil stabilisation with quicklime: influence of lime content and thermal treatment on strength development

This research addresses the field of sustainable construction materials, with particular emphasis on the manufacture of stabilised adobe intended for low-rise buildings and rural housing. It aims to optimise soil stabilisation by adding quicklime, identifying the optimal conditions of lime dosage and controlled thermal curing in order to enhance the mechanical performance of earthen construction materials. The soil was first sieved to 2 mm and then dried at 65 ± 2 °C for 24 hours to ensure initial homogeneity. Standardized prismatic specimens (4 × 4 × 16 cm³) were prepared with different lime contents (3%, 5%, 7%, 9%, 11%, 13%, and 15% by dry soil weight) and subjected to curing durations of 3, 7, and 11 days in an oven at 65 °C. The adopted factorial experimental approach enabled evaluation of the interaction between lime dosage and curing duration. The natural soil water content was estimated at 21.35%, based on the liquid and plastic limits. For each formulation, the mixing water content was adjusted according to the percentage of lime incorporated, in order to maintain a consistent water-to-binder ratio and to ensure adequate lime hydration as well as a homogeneous distribution within the soil matrix. Mechanical performance was assessed using uniaxial compression tests.