Characteristics of Laterite Soil for Potential Geopolymer Applications

Laterite soil is widely found in various tropical and subtropical regions. This study focuses on the physical and chemical properties of laterite soil as a precursor for geopolymer synthesis. The characteristics of the soil were determined through experimental analyses, including XRF, XRD, SEM, EDS, FTIR, TGA/DTA, and pH measurements. XRF analysis revealed that the primary chemical oxides are silica, alumina, and iron oxide, which are very essential for geopolymer production. Both XRD and FTIR assessments revealed that the calcination process applied to laterite diminishes its crystallinity while enhancing its amorphous nature, thereby improving its reactivity. TGA and DTA results confirmed significant weight loss and dihydroxylation between 400 °C and 700 °C, while temperatures above 700 °C showed minimal weight loss and no further dihydroxylation. The pH of the tested laterite soil was measured at 5.35, indicating strong acidic behaviour. Based on these combined chemical and physical analyses, this study concludes that laterite soil is a viable precursor material for geopolymer synthesis.