Review on metakaolin impact on the workability and compressive strength of concrete

Abstract The utilization of supplementary cementitious materials (SCMs) in concrete production has gained considerable attention in recent years, driven by the need for sustainable construction practices and improved concrete performance. Among these materials, metakaolin has emerged as a promising mineral admixture due to its pozzolanic properties and potential to enhance various aspects of concrete behavior. This review examines the extensive research conducted to evaluate the impact of metakaolin on both the workability and compressive strength of concrete. Metakaolin’s influence on compressive strength is due to its pozzolanic reactivity, which contributes to the formation of additional calcium silicate hydrate gel and refined microstructure. Metakaolin addition enhances concrete’s workability and compressive strength, improving ease of mixing and placement. It absorbs water and increases viscosity but can reduce workability by up to 20% and the optimum replacement ratio is between 5% and 15%. Metakaolin significantly impacts concrete workability and compressive strength, with its high reactivity and pozzolanic characteristics causing challenges. However, careful mix design adjustments and incorporation strategies can effectively address these issues. Metakaolin’s contribution to supplementary cementitious reactions and microstructural refinement highlights its potential as a valuable addition to concrete mixtures. Metakaolin’s contribution to supplementary cementitious reactions and microstructural refinement enhances compressive strength, making it a valuable addition to concrete mixtures. Further research on metakaolin’s interactions with concrete constituents will contribute to sustainable and high-performance concrete solutions in the future.