Effects of iron ore tailings (IOT) and lime on engineering properties of problem laterite

Abstract

The results of experimental investigation of lime and iron ore tailing (IOT) admixture on lateritic soil are presented. Preliminary investigations classify the untreated soil as A-6. Compressive strength and soaked California Bearing Ratio (CBR) values of 200 kN/m² and 4%, respectively, further connotes the inadequacy of the soil in terms of engineering requirements. Stabilization test results showed that hydrated lime is effective in modifying the properties of the soil. The addition of IOT to the soil- lime mixtures yielded soil with enhanced properties that met the sub-base and base-course requirement of conventional specification. Specifically, 7-day compressive strength increased from 600 kN/m2 for specimens treated with 8% lime only to 1120 kN/m² for specimens treated with 6% lime and 15% IOT. This value met the 7 days 1035 kN/m² Unconfined Compressive Strength (UCS) evaluation criterion recommended for economic range of lime content for adequate stabilization of problem soils. The CBR improved from 4% for the untreated soil to 70% for soil specimens treated with a combination of 8% lime and 15% IOT.