Stabilization of expansive soil using flyash based geopolymer

Abstract

Expansive soils have a tendency to inflate and shrink in response to moisture content variations. As a result, the soil is severely disturbed, causing significant damage to the building above. The use of additives like lime, fly ash, or cement to stabilize expansive soils is extensively recorded, with the goal of reducing the soil's expansive nature in the past.Despite the fact that lime and cement are frequently employed for expanding soil stabilization, it is now recognized that these traditional admixtures are energy intensive and release a significant amount of CO2.Keeping in view this drawback of these materials, attempts have been made to develop new binding materials which are equally efficient with lower environmental costs. Geopolymer technology, which blends industrial waste materials including fly ash, GGBS, rice husk ash, and alkaline activator to make a paste capable of binding soil particles, was developed.The purpose of this research is to investigate the effects of cement and fly ash-based geopolymer stabilization on expansive soil behaviour. The Unconfined Compressive Strength (UCS) of fly ash based geopolymer stabilized expansive soil rose with increasing binder concentration, according to the experimental results. When the molarity of the activator was increased from 8 M to 10 M, the UCS of fly ash based geopolymer stabilized expansive soil increased, but when the molarity of the activator was increased to 12 M, the UCS decreased. Fly ash based geopolymer stabilized expansive soil specimens with a binder content of at least 20% and an A/B of at least 0.75 revealed higher UCS when compared to cement treated specimens of the same dose. As a result, geopolymer stabilization of expansive soils using fly ash might be considered a more environmentally friendly alternative to cement stabilization.