This investigation presents the experimental studies on the effect of silica fume, alccofine 1203 and both silica fume and alccofine 1203 on high strength concrete. In this study, cement replaced with silica fume, alccofine and both silica fume and alccofine. The replacement percentage varies from 0, 5, 10, 15 and 20%. The experimental investigation is carried out on M50 grade concrete as per IS 10262-2019 and compressive strength results observed at 7 days and 28 days curing. It observed that the compressive strength of conventional concrete (CC) at 28 days is 58.8 MPa, which is greater than the CSF5, CSF10, CSF20, CA5, CA10 and CA20. The compressive strength of CSF15 and CA15 are 2.32% and 4.10% greater than CC. Split tensile strength CSF5A15, CSF10A10 and CSF15A5 are 2.76%, 4.32% and 4.01% higher than CC. Four no of reinforcement concrete beam with 2500 mm length and 150 mm × 250 mm in cross section were test to measure the load and deflection. The failure load of reinforced concrete beam using 15% replacement of cement by alccofine 1203 (CA15) is 3.16% & 4.43% higher than the CSF15 and CSF10A10. Deflection of CSF15, CA15 and CSF10A10 are 18%, 21% 23% respectively. Finally, it is concluded that the replacement cement by silica fume and alccofine 1203 which influence the strength of high strength concrete. The replacement of cement by 15% of silica fume, 15% alccofine 1203 and 10% of silica fume and 10% alccofine 1203 shows better strength on concrete.