Experimental Investigation on Stabilization of Silty Sand Using Fly Ash

In the present work, fly ash is used as an additive for stabilization with silty sand. Geotechnical properties of fly ash and its interaction with soils can lead to a viable solution for its large scale utilization and disposal. The effect of fly ash on geotechnical properties of silty sand stabilized with the optimum percentage of fly ash has been reported. The fly ash in the rate of 5–20% was added, at an increment of 5% and the change in the soil properties was studied. Atterberg’s limits (silty sand is non-plastic), compaction, California bearing ratio and unconfined compressive strength tests were conducted on these soil fly ash mixtures. The effects of 7, 14 and 28 days of unconfined compressive strength were studied for fly ash mixtures. The results indicate that the maximum dry density increases up to 10% fly ash content, and then dry density decreases gradually with an increase in optimum moisture content. The unconfined compression strength is maximum for 15% fly ash content. The California bearing ratio value of the silty sand increases gradually with the addition of fly ash up to 15%, beyond, where a further increase in fly ash percentage is observed to cause a decreasing trend. The improvement in the California bearing ratio value of the silty sand upon the addition of fly ash suggests that it can be effectively used as a subgrade stabilizer for road construction.