Durability of Peat Stabilized with RHA-Based Geopolymer Formed by Adding Pure Alumina

There has been no research done on the influence of freezing–thawing (F–T) on the durability and engineering properties of RHA-based geopolymer stabilized peat. Therefore, this present study aimed to analyze the effect of F–T cycles on physical, mechanical, and mineralogical properties of sapric and hemic peat stabilized by RHA Based geopolymer. For comparison, ordinary Portland cement (cement) stabilized peat was used as the control sample. The sapric and hemic peats stabilized with RHA-based geopolymer and cement were separately subjected to 10 F–T cycles. The experimental results show that RHA-based geopolymer treated sapric and hemic peats have greater UCS values of 2.1 and 1.96 times, respectively, than cement-treated sapric and hemic peats after 28 days of curing, respectively. It was also found that irrespective of the type of peat and binder, the strength of the specimens kept decreasing with F–T cycles. However, the rate of decrease of UCS of RHA-based geopolymer-treated peats is less than cement-treated peats with F–T cycles. Further, RHA-based geopolymer stabilized peats have shown lesser mass loss and volume change with higher residual strength as compared to cement-treated peats. The results were supported by field emission scanning electron microscope (FESEM) micrographs that reveal the presence of smooth and dense cementitious materials before the F–T cycles and the presence of voids and microcracks after the F–T cycles.