Speaker
Description
The repair and strengthening of reinforced concrete (RC) frames is of great importance in ensuring the structural safety and serviceability of buildings after seismic events. Beam-column joints are primary mechanisms for dissipating seismic energy within RC frame structures. During ground motions, these joints accumulate significant energy, which may result in plastic deformations [1]. However, with appropriate retrofitting techniques, many damaged structures can be restored to service. Most conventional retrofitting methods focus on improving the strength and stiffness of RC joints [2], but this approach often overlooks the importance of enhancing energy dissipation capacity, which is a critical factor for long-term structural performance under aftershock sequences.
This study introduces a retrofitting technique that incorporates viscoelastic (VE) materials stiffened with steel plates in beam-to-column joints in RC frames. Unlike traditional methods, this approach not only improves the strength and stiffness of damaged joints, but also enhances their energy dissipation capacity. This additional capacity is particularly important for addressing the risks associated with repeated loading cycles of already weakened structures [3].
The research methodology included numerical simulations conducted using finite element modeling (FEM) in Abaqus. The analysis evaluated the dynamic performance of RC beam-column joints retrofitted with VE materials and steel plates. A comparative study was carried out using the reference models (undamaged and damaged joints) in relation to the retrofitted joints proposed in this study.
It is worth noting that the proposed retrofitting technique not only addresses the strength and stiffness improvement of RC structures, but also enhances the long-term resilience of RC beam-column joints. The findings highlight that by providing greater ductility and damping properties, the proposed method ensures a more resilient seismic response. The described mechanism ensures that the retrofitted joints are better equipped to handle both primary seismic shocks and subsequent aftershocks. A distinct matter and area for further research is an effective way to bond the VE material layer to the concrete surface to ensure that the damping properties are fully utilized.
[1] Yurdakul, Ö., & Avşar, Ö. (2015). Strengthening of substandard reinforced concrete beam-column joints by external post-tension rods. Engineering Structures, 107, 9–22.
[2] Singh, V., Bansal, P.P., Kumar, M., & Kaushik, S.K. (2015). Retrofitting of reinforced concrete beam-column joints using bonded laminates.
[3] Huang, X., Xu, Z., & Xiao, H. (2023). Experimental study on seismic behavior of damaged Beam-Column joints retrofitted by viscoelastic Steel-Enveloped elements. Buildings, 13(3), 702.
