Concrete is the most widely used construction material. However, since the production of cement releases asignificantamount of carbon dioxide (CO₂), global cement production has led to substantial environmental emissions. Inrecent years,supplementary cementitious materials such as silica fume, fly ash, slag, rice husk ash, and metakaolin have been increasinglyusedas partial replacements for cement to enhance high-strength concrete (HSC) by improving performance, durability, energyefficiency, and service life while reducing permeability. Recent studies on metakaolin, a dehydroxylated alumino-silicatematerial,indicate that it is a highly effective pozzolanic material that significantly enhances the strength characteristics of concrete. Oneofthe major advancements in concrete technology is the development of high-performance concrete (HPC), which is widelyusedinprestigious projects such as nuclear power plants, flyovers, and high-rise buildings. This thesis investigates the partial replacementof cement with metakaolin as a mineral admixture in M80 grade high-performance concrete. Cement was replacedwithmetakaolin at levels of 0%, 5%, 10%, 15%, and 20% by weight. The experimental results were compared withthoseofconventional concrete in terms of compressive strength, split tensile strength, flexural strength, and durability characteristics. Keywords: Rice Husk, Slag, Fly Debris, Silicon oxide, Metakaolin and Compresssive Strength.