High Performance Concrete (HPC) has a few characteristics: high strength, high early strength, high modulus of elasticity, high durability and long life in severe environments, low permeability and diffusion, resistance to chemical attack, toughness and impact resistance and so on. Almost 70 to 80% of the volume of the concrete is occupied by aggregate which have a great impact on characteristics and properties of a concrete. Not only course aggregate but fine aggregate also contributes a lot toward the performance of HPC. Thus, this research studied on the influence of various sand gradations on mechanical properties and concrete quality of HPC. The sand gradation utilized in the study are normal size sand, sand passing through sieve size 1180µm, sand passing through sieve size 600µm and sand passing through sieve size 300µm. The mechanical properties of HPC being studied are compressive strength and splitting tensile strength while the concrete quality of HPC is determined by using water absorption and Ultrasonic Pulse Velocity (UPV) test. The results show that the mechanical properties and concrete quality increased as the size of sand particles decreased. The optimum sand gradation is the sand passing through sieve size 300µm which achieved highest mechanical properties and concrete quality showing the highest result of compressive strength (123.9MPa), splitting tensile strength (8.91N/mm2), lowest percentage of water absorption (0.55%) and highest UPV value (7743N/mm2).
