Sustainable geopolymerization approach to stabilize sabkha soil

Sabkha soils, which predominately exist in arid/semi-arid climate zones worldwide, have raised considerable concerns because of their high compressibility and low bearing capacity. This study aimed to assess the feasibility of stabilizing saline sabkha soil through geopolymer treatment using environment-friendly materials. Untreated and treated specimens were characterized using standard proctor compaction, direct shear, and unconfined compressive strength (UCS) tests, field-emission scanning electron microscopy/energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The effects of alkaline activator molarity, fly ash concentration, and curing period were investigated. ANOVA and response surface method were utilized to assess the influence of the investigated variables on the produced UCS data set. Results revealed that the enhanced UCS of the geopolymer-treated specimens was highly influenced by the molarity of NaOH. In addition, the alkaline activation of sabkha soil incorporating fly ash had higher UCS and shear strength than the untreated and Ordinary Portland cement (OPC) treated specimens.