Abstract
•The formation of the highest cementitious product and geopolymeric gel NASH for the novel geopolymer.•The CASH gel co-existed along with the highest cementitious product due to the inclusion eggshell powder.•Curing of samples at 50 °C for 7 days resulted in well-reacted precursor particles.•The geopolymeric gel reinforced the clay particles filling the voids.•Eggshell powder-flyash geopolymer can substitute cement in soft soil stabilization.
The morphological and microstructural evolution of flyash (FA), eggshell powder (ESP), and soft soil (S) geopolymer was studied. The variable parameters for synthesis was precursor concentration (10 %, 20 %, 30 %, 40 %, and 50 %) in soft soil, whereas ESP:FA ratio as 50:50, Na2SiO3:NaOH ratio as 70:30, and curing condition as 50 °C for 7 days were the fixed parameters. The effect of these parameters on the geopolymerization was explained using field emission gun-scanning electron microscopy including an energy dispersive X-ray spectrometer and mapping. The calcium aluminate silicate hydrate gel co-existed along with the highest cementitious product. The geopolymeric gel structure filled the voids between soft soil particles and reinforced the whole matrix.