Study of the Mechanical Behaviour of a Clayey Soil Under Normal and Frozen Conditions

Lime and cement are quite compatible for stabilizing clayey soils; changes in a thermal regime may inversely affect the advantages of stabilized soil. The present study interprets changes in the mechanical behaviour of frozen and unfrozen Himalayan soil samples through an unconfined compressive strength test. The soil was treated with ground eggshell powder (3%-9%) and alkali activator (Sodium chloride) (2%-6%); it was reinforced with arbitrarily distributed polypropylene fibers (0.05%-0.15%). Standard 7, 14 and 21-day-old soil specimens were tested in unfrozen conditions, while fresh 21-day-old soil specimens were tested after 3, 5 and 10 freeze-thaw cycles. The design of the experiments was based on the Taguchi technique and arranged in an orthogonal array. The results of the research clearly show that poultry waste (eggshell powder) and alkaline soil stabilizer improved the strength behaviour of the subject soil. On the other hand, the polypropylene fibers played an important role in changing the brittle behaviour of the stabilized soil to ductile behaviour. The sudden collapse of a structure may be avoided by using polypropylene fibers.