Effects of continuous leaching on engineering properties of lime-stabilized lateritic soils

Abstract

This research investigates the performance of lime-stabilized lateritic subgrades under continuous leaching by focusing on changes in the engineering properties of the natural soil together with those treated with varying proportions of lime. Geotechnical tests conducted include California bearing ratio (CBR), Atterberg limits, particle size analysis and Proctor compaction tests. The leaching test was conducted in a constant-head cylindrical Perspex tank for a period of 28 days. X-ray diffraction analysis was conducted on the extracted leachates coupled with other physicochemical tests such as pH, electrical conductivity (EC), and calcium and potassium concentrations. The experimental results indicate that the highest CBR value of 47.1% was obtained from the mixture containing 5% lime after a curing period of 7 days. Further increase in the amount of lime resulted in a decrease in CBR, except for the 10% soil-lime mixture which had a CBR value of 31.4% after a curing period of 28 days. Physicochemical analyses showed a significant decrease in EC, calcium and potassium concentrations from the pore fluid of the soil-lime mixtures. The results suggest that the potential for strength loss was higher in the mixtures stabilized below their optimum lime contents than in those stabilized above their optimum lime contents.