A Comparative Study on Geo-Technical Characteristics of Sedimented and Compacted Fly Ash Bed Treated with Lime Column

Abstract

This paper highlights the effect of lime column in improving the geotechnical characteristics of sedimented and compacted fly ash. In this experimental investigation, large scale laboratory models of sediment and compacted fly ash beds were prepared with a centrally installed lime column simulating a field condition as closely as possible. After the curing periods of 30, 90, 180 and 365 days, the undisturbed fly ash specimens were collected from different radial distances and depths to study the improvement in various properties such as water content, dry density, unconfined compressive strength, and hydraulic conductivity. From the test results, it was found that lime column treatment is an effective means of increasing the unconfined compressive strength and reducing hydraulic conductivity of fly ash deposits along with modifying other geotechnical parameters including water content, density and shear parameters. A comparative study showed that the strength and dry density of stabilized fly ash specimens collected from compacted fly ash are much higher than that of sediment fly ash bed whereas the hydraulic conductivity value was found to be less in the samples collected from the compacted fly ash bed than that of sedimented fly ash beds.