This paper presents the flexural capacity of reinforced concrete beams designed with high-strength steel bars. Reinforced bars fy = 550 MPa are to have flexuralstrength like bar 420 MPa. According ACI 318M-19, (fy =550 MPa) allowed use as reinforcing steel, which previously unpermitted. study was conductedto represent possibility using reinforcement. There five sample thatdesign various diamete...