This study investigates the flexural behavior of Ultra-High Performance Reinforced Concrete (UHP-RCC) beams enhanced with microsilica, quartz, fly ash, and steel fibers. The objectives of the study are to assess the influence of these additives on the mechanical performance and structural integrity of UHP-RCC beams, and to contribute to the understanding of their potential in real-world construction projects. In this study, the flexural behavior of Ultra-high performance reinforced concrete beams, which have of various quartz percentages as a replacement for fine aggregate, fly ash, and micro silica as a partial replacement for Portland cement This is to find the best possible mixture and In this research, 45 concrete cubes made of 15 different concrete mixtures, each with a Different ratio of the constituent materials, it was poured and cured in water for seven days. By analyzing its strength eliminated cubes after which select the four performance Combinations that perform the best. The ideal combinations used to cast four beams and curing for 28 days. In order to create the four reinforced concrete beam specimens for the investigation, each measuring (1550 x 200 x 150) mm, four different concrete formulations were used. Furthermore, for reference, a control specimen with the same dimensions was made. Flexural tests on these specimens showed that the addition of steel fibers, fly ash, quartz, and microsilica significantly increased their flexural strength. When comparing the load-carrying ability of the control specimen to the four reinforced concrete beams, this improvement was clear. Whereas it outperformed the control sample by 28% in that area. In addition, four specimens of non-reinforced concrete beams measuring 500 x 100 x 100 mm were prepared for the investigation, and a control beam with the same measurements was also included. A three-point load test was used to test these specimens. When comparing the rupture specimens to the control specimens, the results amply demonstrated that the components included in the concrete mixes significantly increased the modulus of the rupture specimens. This strength gain was very noticeable, as it outperformed the control sample by a margin of 224.3%. For every concrete combination, three cube specimens of (100 x 100 x 100) mm were also made, along with three control cubes of the same size. A cube compressive strength machine test performed on these cubes demonstrated the better strength properties of the concrete as well as its superior quality when compared to the control specimens. Compressive strength increased noticeably as a result of this. In cases when it outperformed the control sample by %152