Enhancement of strength characteristics of Clayey Sand using fly ash and geonet

Abstract

India being a developing country, tones of industrial waste byproducts are generated every year and the quantity of waste keeps on escalating with time. In recent times, improving the subgrade strength by using soil reinforcement such as geosynthetics and by utilizing industrial wastes which if left unutilized pollutes the environment, is gaining lot of importance. In the present work, an experimental investigation has been carried out to improve the soil strength by adding fly ash (FA) and by reinforcing the soil using geonet. Locally available soil used in the experimental work was classified as SC soil (Clayey Sand) based on its index properties. Soil was mixed with variable percentages of FA, 10%, 14%, 18%, 22% and 26% to decide the ideal percentage of FA for which maximum gain in soil strength was witnessed in Unconfined Compression test and soaked CBR test. Geonet was placed at varying depths of one fourth the depth (H/4), half the depth (H/2) and three fourth the depth (3H/4) from top of soil specimen to determine the ideal depth of placement of geonet for which the soil exhibited maximum gain in strength in soaked CBR test. Based on the experimental results, soil with 18% FA showed maximum increase in UCC strength of 156.19 kPa and soaked CBR value increased by approximately 2.55 times that of control specimen. Soil reinforced with geonet placed at three fourth depth from top showed maximum strength gain in soaked CBR test.