This study investigated the mechanical properties of high-performance concrete (HPC) with the percentage of mineral admixtures. HPC is a good choice for multi-story buildings because it has many advantages. As HPC becomes more popular, it is important to research its properties. This study used the P.C. Aitcin method to design HPC mixes with compressive strengths of 60 to 80 MPa. Fly ash is used for M60 and M70 grade HPC and Silica Fume is used for M80 grade HPC is used as mineral admixture as a 20% replacement for cement. In this research paper, the study of properties of the different ingredients used to make HPC is carried out. The testing of three concrete mixes for mechanical properties such as compressive strength, split tensile strength, modulus of elasticity, and flexural strength, as well as other important properties is done. This study explores High-Performance Concrete (HPC) by precisely controlling the water-to-cement ratio and incorporating mineral and chemical admixtures, achieving strengths from 60 to 80 MPa. It investigates key mechanical properties, establishes empirical equations, and compares findings with codes and literature. The results showed that a lower water-to-binder ratio (w/b) led to better mechanical properties. The experimental program includes the casting of 39 cubes, 39 cylinders, 39 beams and 81 columns to test the physical properties of different concrete grades. The use of a compression testing machine with a load capacity of 3000 kN to test the HPC cubes and a loading frame with a load capacity of 2000 kN to test the columns. The average compressive strength for HPC M60 to M80 was 65.40 MPa, 73.45 MPa, and 82.64 MPa respectively. The modulus of elasticity values ranged from 40 to 50 GPa. The findings of the study showed that an increase in concrete strength correlated with a decrease in the average value of Poisson's ratio. Overall, the study suggests that HPC is a good choice for high-rise buildings because it has many advantages. As HPC becomes more popular, it is important to research its mechanical properties. This study provides valuable results about the mechanical properties of HPC in comparison with IS 456:2000. From the experimental results of tested columns, it was observed that as the load increased, the deflection decreased for both uniaxially and biaxially loaded columns, highlighting the novelty of this finding. Additionally, the columns subjected to biaxial loading displayed greater sensitivity compared to their axial and uniaxial loading.
