Flexural behavior of hybrid fiber reinforced UHTCC ‐NC composite beams: Experimental and numerical investigations
Fangwen Wu, Yihe Zhang, Ao Chen, Lanqing He, Zirun Li, Haipeng Lei, Yateng Ma Abstract
The flexural behavior of hybrid fiber reinforced ultra‐high toughness cementitious composites (UHTCC)‐normal concrete (NC) composite beams was explored through four‐point bending tests in this study. The results showed that the application of hybrid fibers in composite beams offers certain advantages in crack width control and bearing capacity. The stiffness of the hybrid fiber reinforced UHTCC‐NC composite beams mixed with steel fiber (SF) and polyethylene (PE) fiber in the crack development stage was significantly higher than that of the composite beams mixed with a single fiber, with a maximum improvement of 30.5%. The number of cracks in the pure bending zone increased, and the maximum crack width was reduced compared to that of the NC beam. The cracking and yield loads of the composite beams mixed with steel and polyvinyl alcohol (PVA) fibers were higher than those of the NC beam. Based on the UHTCC constitutive model, finite element (FE) models were developed to predict the flexural behavior of hybrid fiber reinforced UHTCC‐NC composite beams. A comparison with the experimental results demonstrated that the FE model could accurately predict the flexural behavior of composite beams (load–deflection curve and failure modes). Based on the finite element analysis (FEA), the structural evolution of the composite beams was discussed. Finally, a comprehensive FE parametric analysis was conducted, including the UHTCC layer thickness, reinforcement ratio, and reinforcement strength grade.