Durability of Zein-Treated Sand under Wetting-Drying Cycles

Zein biopolymer, extracted from the maize endosperm using a benzene solution, has been used to enhance the strength of cohesionless sands. This study investigates the durability of zein-treated sand under wet-dry cycles. Specimens are prepared by mixing sand with various biopolymer contents under dry conditions. After mixing with a solvent containing 70% ethanol, the zein-treated sands are cured for 7 days at room temperature. Subsequently, the specimens are subjected to 0 to 10 wet-dry cycles, each involving 24 h of water immersion followed by 24 h of air drying at 40°C. The durability of the treated specimens is evaluated using unconfined compression tests after each wet-dry cycle. A comparative analysis is performed to evaluate the effects of biopolymer content and the number of wet-dry cycles on the compressive strength. The experimental results show that zein treatment significantly enhances the strength and durability of the sand. The strength of the treated sand decreases with increasing number of cycles and varies with biopolymer content. Therefore, zein biopolymer can be used for stabilizing cohesionless soils in regions prone to fluctuating moisture conditions.