Utilization and Geopolymerization of Fly ash for Concrete Preparation and Soil Stabilization: A Short Review

Abstract

Geopolymers are green composite materials developed by the alkali treatment of aluminosilicate wastes such as fly ash. Over the last 30 years, different applications of geopolymer binders, which include the production of green concrete, coating material, bricks, and as a method of stabilization of soil have been studied. This review paper primarily concentrates on the employment of fly ash for concrete preparation and soil stabilization through this novel geopolymer technology. Therefore, the first part of the paper highlights the advantages and properties of fly ash-based geopolymer while the second part describes its utilization as a method of soil stabilization for geotechnical applications. The fly ash is mixed with an alkaline solution to form a paste that binds the coarse and fine aggregates together to produce concrete. The findings of the past research studies have been highlighted in this paper, which shows that fly ash derived geopolymer exhibits higher compressive strength, better durability properties, when matched with traditional cement-based concrete. Further, in the context of geotechnical engineering, soil stabilization is the moderation of soil properties to obtain a type of soil that remains in an unchanged condition throughout its serviceable life. Use of geopolymerized fly ash as a method of soil stabilization includes developing a geopolymer paste i.e. fly ash added to alkaline activator, then adding it with varying percent to the soil. As a result of geopolymeric reactions, the soil becomes chemically stable, which increases the coherence of the soil particles. Past literature demonstrates that soils may be stabilized to enhance their strength and to reduce plasticity. The finding of this paper suggests that fly ash, through geopolymerization, could be successfully used for concrete preparation and soil stabilization.