Improving the bearing resistance of subgrade sandy soil using hydrated lime

Abstract

Soil stabilisation refers to any process by which the strength, stiffness and bearing capacity of road foundations are improved by mechanical, chemical, electrical, or thermal means. The main aim of this research was to estimate the optimum lime content (OLC) required to stabilise a loose sandy soil, and to achieve this aim, experimental work was carried out to evaluate the characteristics of lime-treated sand based on determining maximum dry density (MDD), optimum moisture content (OMC), and soil bearing resistance (CBR) at 1, 3, and 7 days’ curing. The hydrated lime was used in proportions of 0, 4, 6, 8, and 10% by dry weight of the soil. The results indicated that the MDD increases as the lime proportion increased from 0 to 8%; however, a slight reduction in the soil density was observed at 10% lime inclusion. Additionally, the results revealed that the soil bearing resistance under both socked and unsocked conditions were improved significantly with increasing lime content. Overall, addition of 8% lime with 7 days’ curing duration, improved the stability and strength of subgrade sand soils. The findings of this work thus confirm the benefit of adding lime in field application stabilisation schemes for geotechnical and pavement engineers.