Study on Fly Ash-Based Geopolymer Concrete for Rural Road Construction in India

Fly ash-based geopolymer concrete (FAGPC) presents a viable alternative to traditional Portland cement-based concrete for rural road construction. Unlike conventional concrete, which relies on Portland cement, FAGPC utilizes fly ash—a byproduct of coal combustion at power stations—as its primary binder. This shift results in a concrete with a significantly lower carbon footprint and reduced energy consumption. Geopolymer concrete is formed through a reaction between silica-rich and alumina-rich materials with an alkaline solution. The present study evaluates FAGPC against M40-grade OPC concrete over curing periods of 7, 14, and 28 days, focusing on their strength properties. The findings indicate that FAGPC offers comparable or slightly superior performance to M40-grade OPC concrete. Additionally, scanning electron microscopy (SEM) was used to analyze the microstructure of FAGPC, while durability tests in acidic and sulfate environments demonstrated its enhanced resistance to corrosive conditions by over 2.5%. A cost-benefit analysis revealed that FAGPC is more economical, with preparation costs of Rs. 3061.18 per cubic meter compared to Rs. 4701.30 for OPC concrete, resulting in savings of Rs. 1640.12 per cubic meter, or approximately 35%. The study concludes that FAGPC is a cost-effective and environmentally friendly option for highway and pavement construction, contributing to the growing research on sustainable construction materials.