Partial Replacement of Cement with Fly ash in Concrete

This research investigates the utilization of fly ash, a byproduct of thermal power plants, as a partial replacement for cement in M25 concrete, aiming to enhance sustainability and mitigate environmental impact. The study focuses on evaluating the mechanical properties of concrete mixes incorporating varying percentages of fly ash, specifically 0%, 10%, 20%, 30%, and 40% by weight of cement. Compressive strength tests were conducted on concrete samples cured for 7, 14, and 28 days to assess the impact of fly ash on strength development over time. The experimental results revealed that the inclusion of fly ash significantly influences the compressive strength of M25 concrete. At early curing ages (7 days), mixes with higher fly ash percentages exhibited a slight reduction in compressive strength compared to the control mix (0% fly ash). However, as the curing period progressed, particularly at 28 days, a notable trend emerged. Concrete mixes incorporating fly ash demonstrated improved compressive strength, with the 20% and 30% fly ash replacement showing optimal performance. This indicates that fly ash contributes to long-term strength gain due to its pozzolanic reactions. By effectively utilizing this industrial byproduct, the environmental burden associated with cement production can be reduced, while simultaneously enhancing the long-term mechanical properties of concrete. Future research should explore the durability characteristics of these mixes and optimize the fly ash percentage for specific applications. Key Words: Fly Ash (FA), Workability, Compressive Strength, Split Tensile Strength, Flexural Strength.