Sustainable soil stabilization using combination of geotextile, fly-ash and saw dust for pavement subgrade

Purpose: This paper investigates the combined effect of fly ash, sawdust and geotextile in stabilizing the soil. Design/methodology/approach: A thorough geotechnical testing was carried out in order to study the potent characteristics of soil and soil mixes. The present investigation was set up in two stages. In the first stage, effects of fly ash (5, 10, 15 and 20%), sawdust (2.5, 5 and 7.5%) and layers of geotextile placed at different depths were studied separately to determine their effect on soil stabilization. In the second stage, fly ash, sawdust and geotextile were mixed with soil sample in order to obtain the optimum dosage which can be used for stabilization of soil i.e. their combined effect as stabilizer on soil stabilization. Findings: It was observed that by introducing fly ash, sawdust and geotextile to the soil, the CBR values increase and thickness of pavement layer decreases. It also decreases the amount of stress on subgrade leading to enhancement of pavement stability with cost effectiveness. Research limitations/implications: Economical use of industrial waste has been proposed in the present research which otherwise prove to be a malady to climatic change and human health. From the study, an optimum dosage of fly ash (2.5%) and saw dust (5%) and depth for geotextile (6 cm) has been proposed. Originality/value: The article explores the possibility of a ternary blend, i.e., geotextile, fly-ash and saw dust on effectively stabilizing pavement subgrade. Limited literature was available to address the issue of utilizing the industrial wastes that otherwise pose disposal issues.