NEXCEL Project Paper 39
Release time: 2025/12/23 Publisher： original Views：
Seismic performance and shear strength of HECC/RCbeam-column joints with simpliffed reinforcement
Prof. Bai Yulei from Beijing University of Technology, Principal Investigator of NEXCEL 2024 SFP project ‘Application and demonstration of FRP tube - concrete new composite structure,’ has published a paper entitled "Seismic performance and shear strength of HECC/RCbeam-column joints with simpliffed reinforcement" in "Journal of Building Engineering" (SCI) recently.
Abstract：
The application of high-performance materials presents an effective strategy to enhance the performance of structural components. To improve the seismic behavior and ductility of beamcolumn joints while mitigating reinforcement congestion, a high-performance hybrid ffber reinforced (1% vol polyethylene ffbers and 1% vol steel ffbers) cementitious composite (HECC) was applied in the joint core region. Five HECC/reinforced concrete (RC) composite joint specimens considering stirrup ratio in the core region, axial compression ratio, and HECC strength were designed and tested in this study. The results demonstrated that the application of HECC signiffcantly enhanced the ductility characteristics during shear failure in the joint core region, achieving a shear capacity reserve 34% greater than that of conventional RC joints. In addition, the specimens maintained structural integrity after failure, with micro-cracks being distributed more uniformly. Unlike RC joints, the contribution of transverse rebars on the bearing capacity of HECC joint was less signiffcant, as evidenced by only a modest 7% increase in bearing capacity at a 2.10% stirrup ratio, indicating that the ffber bridging effect of HECC provided a constraint effect similar to that of transverse rebars. Furthermore, existing calculation formulas tend to signiffcantly underestimate the shear capacity of HECC joints. Therefore, a revised formula was proposed to enhance an existing model for HECC beam-column joints by incorporating a synergistic enhancement coefffcient. This modiffcation improves accuracy in predicting the shear strength of HECC joints, achieving an average predicted-to-test ratio of 1.013 and a coefffcient of variation of 0.096.
Paper Details:
Journal of Building Engineering 108 (2025) 112910
https://doi.org/10.1016/j.jobe.2025.112910