Simplified Unified Model for Flexural Capacity of Ductile HPC Beams with A Low Reinforcement Ratio

There is no specific model to predict the flexural capacity of ultra-high-performance concrete (UHPC) beams with a low reinforcement ratio. Accordingly, a comprehensive experimental database containing ۱۶۲ datasets was gathered from literature to propose an explicit analytical model containing various critical features, including fiber volume fraction, fiber aspect ratio, fiber strength, water-to-binder () ratio of mixture, and reinforcement ratio. Additionally, a supplementary experimental study involving a large-scale UHPC beam with a very low reinforcement ratio (almost negligible) was conducted to verify the model's performance. The findings revealed that the proposed bending model achieved an IAE of ۱۰.۸% and a COV of ۱.۰۴, indicating its high accuracy in comparison to a comprehensive experimental dataset comprising ۱۶۲ large-scale beam tests. Furthermore, the comparison between the experimental results of the tested beam and the proposed model showed a deviation of ۴.۵%, which supports the effectiveness of the flexural capacity formulation. A parametric statistical analysis was conducted using Minitab software to evaluate the influence of key parameters affecting the roles of fiber and matrix.There is no specific model to predict the flexural capacity of ultra-high-performance concrete (UHPC) beams with a low reinforcement ratio. Accordingly, a comprehensive experimental database containing ۱۶۲ datasets was gathered from literature to propose an explicit analytical model containing various critical features, including fiber volume fraction, fiber aspect ratio, fiber strength, water-to-binder () ratio of mixture, and reinforcement ratio. Additionally, a supplementary experimental study involving a large-scale UHPC beam with a very low reinforcement ratio (almost negligible) was conducted to verify the model's performance. The findings revealed that the proposed bending model achieved an IAE of ۱۰.۸% and a COV of ۱.۰۴, indicating its high accuracy in comparison to a comprehensive experimental dataset comprising ۱۶۲ large-scale beam tests. Furthermore, the comparison between the experimental results of the tested beam and the proposed model showed a deviation of ۴.۵%, which supports the effectiveness of the flexural capacity formulation. A parametric statistical analysis was conducted using Minitab software to evaluate the influence of key parameters affecting the roles of fiber and matrix.

کلیدواژه ها:

Beam ، HPC ، Flexural Capacity ، Low Reinforcement Ratio ، Fiber Role