Performance Evaluation and Enhancement of Geopolymer Concrete using Silica Fume

ABSTRACT

This study investigates the effects of Silica Fume (SF) on Geopolymer Concrete (GPC) to evaluate its impact on key performance metrics, including workability, setting times, and mechanical properties. Geopolymer concrete mixes with varying SF/Fly Ash (FA) ratios were prepared and tested for the slump, initial and final setting times, compressive strength, and splitting tensile strength. Results indicate that increasing SF content decreases slump values, reflecting reduced workability due to the high surface area and water absorption of SF particles. Incorporating SF significantly accelerates setting times, which is advantageous for applications requiring rapid strength gain. Mechanical testing revealed a marked improvement in compressive and splitting tensile strengths with higher SF content, attributed to enhanced microstructural densification and reduced porosity. Despite these promising findings, the study identifies several knowledge gaps, including the need for research on long-term durability, optimization of mix proportions, standardization of production methods, exploration of additional industrial by-products, and comprehensive environmental and economic assessments. Addressing these gaps will advance the understanding and application of SF-blended GPC, supporting its broader adoption in sustainable construction practices.