Document Type : Research Paper
Abstract
The influence of lime on the shear strength of soil has been known for centuries. The conventional method to increase the lime content of a soil is to add less than 10% hydrated lime in the form of powder or grout to the soil. This method is convenient for soils to be used as fill material in projects such as road construction, land fill pavements or lime pile; but is not applicable where a large quantity of naturally occurring soil requires treatment, such as on a slope experiencing slippage. In this research, a new method is examined by which a lime-saturated solution of water permeates the soil. A physical laboratory model was designed, built and tested. The results of a 60 day test showed that the pozolanic reaction between soil particles and the dissolved calcium ions developed cementation between soil aggregates, leading to a significant increase in the soil shear strength. The results of a series of direct shear and Atterberg limit tests carried out on treated and untreated samples demonstrated an increase of 300% and 220% in cohesion and the internal friction angle, respectively. It also showed a decrease of 14% in the plasticity index of the soil resulting from the intrusion of hydrated lime equivalent to a mere 0.5% of the soil mass.
Keywords
)