Durability of peat stabilized by RHA based geopolymer formed by adding pure alumina and bauxite powder

Abstract

This study examines the effect of N_wd cycles on unconfined compressive strength (UCS), pH, electrical conductivity (EC), mass loss (ML) of treated sapric, fibric and hemic peat. The two types of rice husk ash (RHA) based geopolymers are formed by adding two different sources of extra aluminium as pure Al₂O_3, referred to as G1, and bauxite referred to as G2. For comparison, ordinary Portland cement was selected as a control sample. From the results, the UCS of geopolymer treated peats show more strength than cement treated peats because the hydrotalcite phases of geopolymer fill the voids more efficiently. However, the rate of decrement of UCS in both geopolymer treated peats is more than cement treated peats because the increased number of micropores in geopolymer treated peats. The field emission scanning electron microscope (FESEM) micrographs show dense and smooth cementitious products before N_wd cycles consistent with X-ray diffraction (XRD) results and show the existence of micropores after N_wd cycles for geopolymer treated peats. Fourier transform infrared spectroscopy (FTIR) confirms the results of XRD as it shows the adsorption bands of aluminosilicates, which form the basis of geopolymerization, and further confirms the existence of cavities and cracks in samples after N_wd cycles.

Keywords:

• Peat
• RHA
• geopolymer
• durability
• wetting-drying cycle
• microstructure

Availability of data and material

Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.

Authors’ contributions

Suhail Ahmad Khanday: Writing-Original draft preparation, Conceptualization, and Methodology. Dr. Monowar Hussain: Supervision, Investigation, Reviewing and Editing. Dr. Amit Kumar Das: Supervision.

Disclosure statement

No potential conflict of interest was reported by the authors.