Parametric Study on Partial Replacement of Fine Aggregate by Bottom Ash along with Glass Fiber for Sustainable Concrete

This research investigates the synergistic mechanical and durability performance of sustainable concrete incorporating industrial coal bottom ash (BA) as a partial replacement for fine aggregate, alongside alkali-resistant glass fibers (GF). With the global construction industry striving to mitigate environmental footprints, utilizing co-products like bottom ash alleviates landfill pressures while glass fibers enhance post-cracking ductility and tensile strength. A comprehensive experimental program was conducted across varying mix proportions: fine aggregate was replaced with bottom ash at 0%, 10%, 20%, 30%, and 40% by weight, combined with a fixed dosage of 0.5%, 1.0%, and 1.5% glass fibers by volume. Evaluated parameters include workability (slump cone test), compressive strength (7, 28, and 56 days), split tensile strength, flexural strength, and water absorption characteristics. The experimental results demonstrate that an optimal replacement of 20% bottom ash combined with 1.0% glass fiber yields a 28-day compressive strength of nearly same over control mix, while concurrently improving split tensile strength by 18.4% and flexural toughness by 24.2%. This parametric evaluation establishes a viable pathway for producing eco-friendly, high-performance structural concrete