Geopolymer Concrete Using Bottom Ash as Fine Aggregate

Abstract

The present study explores performance of geopolymer concrete (GPC) using GGBFS as a Entire replacementfor OPC and bottom ash incorporated as a substitute for natural fine aggregate. Bottom ash was incorporated at replacement levels ranging from 0% to 50%, while NaOH and (Na₂SiO₃) served as alkaline activators. The workability of fresh concrete was evaluated using slump cone and compaction factor tests, whereas compressive strength and split tensile strength were determined after 7 and 28 days of ambient curing. The results showed that the mechanical properties improved with increasing bottom ash content up to an optimum level and decreased thereafter due to the porous nature of bottom ash. The mix containing 30% bottom ash (M-GPCB30) exhibited the best overall performance in terms of strength and durability. The findings demonstrate the potential of bottom ash as a partial alternative to river sand in GPC, enhancing sustainability in the construction industry by the utilization of industrial by-products and reducing environmental impacts.