Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering)

This study investigates the flexural performance of ultra-high-performance fiber-reinforced concrete (UHPFRC) beams in which cement was partially replaced (0, 10%, and 20%) with sugarcane bagasse ash (SCBA), rice husk ash (RHA), and fly ash (FA). In the experiment, seven beams were tested under a four-point loading test to evaluate their flexural behavior. The experimental findings stated that the optimum structural performance occurred at 10% replacement with SCBA and RHA, which enhanced the flexural capacity, stiffness, and toughness of UHPFRC beams. The ultimate moment capacity of UHPFRC beams incorporating SCBA and RHA as cement replacements with 10% has increased by 7.3% and 12.2%, respectively, whereas a reduction of 9.80% was caused by incorporating 10% FA. Optimal results are achieved at 10% substitution with RHA or SCBA, which provides the best synergy between environmental benefits, and structural efficiency. Eventually, an analytical validation using design codes and various prediction equations confirmed good agreement with experimental results. This research combines full-scale flexural testing, comparative waste-based SCM assessment, and multi-criteria sustainability analysis for UHPFRC beams, thereby providing valuable experimental evidence and design-oriented insights for the development of low-carbon and structurally efficient UHPFRC applications.