V3I6P100

Comparative Evaluation of Eco-Friendly Concrete Incorporating Industrial and Marine Waste Materials: Pulverized Fuel Ash and Oyster Shell Ash

Shaswat Tiwari¹, Prof. Kamlesh Kumar Choudhary²

Abstract

This study investigates the effect of partial replacement of cement with Pulverized Fuel Ash (PFA) and Oyster Shell Ash (OSA) on the properties of M30 grade concrete. The mix design was carried out as per IS 10262 with a target mean compressive strength of 38.25 MPa. A control mix (M30-C) and modified mixes with a constant 30% total replacement of cement (varying proportions of PFA and OSA) were prepared. Workability of fresh concrete was evaluated using the slump test, which increased from 80 mm (control mix) to 96 mm at 30% replacement, indicating improved workability. The compressive strength at 7, 14, and 28 days showed progressive strength gain. At 28 days, the control mix achieved 38.20 MPa, while the optimum mix M-P15-O15 (15% PFA + 15% OSA) reached a maximum compressive strength of 40.17 MPa, representing an increase of approximately 5.2%.

Similarly, the split tensile strength and flexural strength at 28 days for the optimum mix were found to be 3.55 MPa and 4.45 MPa, respectively, compared to 3.45 MPa and 4.33 MPa for the control mix. However, at higher replacement levels (e.g., M-P30-O0), the compressive strength decreased to 37.23 MPa. Cost analysis revealed that the optimum mix reduced the cost of concrete from ₹5951/m³ (control mix) to ₹5139/m³, resulting in a saving of approximately 13.6%. The study concludes that partial replacement of cement with 15% PFA and 15% OSA provides optimum performance in terms of strength, workability, and economy, making it a sustainable and efficient alternative for concrete production.

Keywords:

Pulverized Fly Ash (PFA), Oyster Shell Ash (OSA), OPC cement, Compressive Strength, Workability, Cost Analysis.