Shear strength and durability against wetting and drying cycles of lime-stabilised laterite soil as subgrade

Abstract

Laterite soil is commonly used as a fill or pavement material. However, it tends to lose its natural bonding and experiences large deformation when subjected to cyclic rainy (wet) and hot (dry) seasons. This leads to cracking and deflection of road pavement. It has long been known that lime stabilisation can improve the engineering properties of laterite soils. Unconfined Compressive Strength (UCS) tests at different curing periods (0, 3, 7, 14, and 28 days) were conducted with various percentages of lime (3%, 5%, 7%, and 9%). The durability of stabilised soil against wet and dry cycles was also evaluated. In addition, the variation of shear strength parameters during the Consolidated Undrained (CU) triaxial test under different confining pressures has been presented. Microstructural analyses showed an increased soil strength due to the formation of calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH).