Geotechnical Properties and Applications of Iron Ore Tailings-Amended Lateritic Soil for Road Construction

The abundance of lateritic soils in Nigeria has made them one of the most used materials for road construction. However, many of these soils exhibit substandard geotechnical properties, necessitating improvements before their deployment in road construction. This study aims to evaluate the geotechnical properties and practical applications of iron ore tailings (IOTs)-amended lateritic soils for road construction. The lateritic soil obtained from a road construction burrow-pit as well as the mixture with IOTs were subjected to mineralogical and geotechnical tests. The lateritic soil contains appreciable amounts of clay (29.1%), fines (52.4%) and sand (46.6%) with a small quantity of gravel (1.0%). Thus, they can be described as clayey sand. In addition, an investigation of its consistency limits indicates that the soil plots above the A-line and classified as highly plastic clay based on their position on the Unified Soil Classification System (USCS) chart. The results of the geotechnical properties indicate a significant improvement in the geotechnical properties of the lateritic soil with the addition of IOT. There was an increase in maximum dry density and California bearing ratio (CBR) with a reduction in the values of liquid limit, plasticity index, linear shrinkage, and unconfined compressive strength. This study demonstrates that the geotechnical properties of the lateritic soil can be modified to fulfil the standard required for utilization as a road subbase and the minimum required can be suitably achieved by mixing about 20% IOTs with lateritic soil.