Experimental investigation of Corner RC Beam-Column Joints Subjected to Unidirectional and Bidirectional Lateral Loading

مهندسی عمران فردوسی

Article 6, Volume 38, Issue 3 - Serial Number 51, August 2025, Pages 115-142   

Document Type: Original Article

DOI: 10.22067/jfcei.2025.93466.1356

Authors

Seyyed Ahmad Nezami¹; Ahmad Shooshtari^{* 2}; Jalil Shafaei³

¹Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

²Civil Engineering Department,, Ferdowsi University of Mashhad, Mashhad, Iran

³Department of Civil Engineering, Shahrood University of Technology, Shahrood, Iran

Abstract

The most important aspect of the stability of reinforced-concrete (RC) buildings against lateral movements caused by earthquakes is maintaining the elastic behavior of the joint area. Therefore, the most important task in the seismic resistant system of the moment frame is the beam-column joints. In this research, the seismic behavior of the corner joint substructure under the influence of bi-directional loading is evaluated experimentally. The studied asymmetrical joints include three categories: 1-with seismic details according to the ACI318-19 standard, 2-without seismic details, due to the absence of transverse reinforcement in the joint area and 3- Has second-class weakness and also insufficient bond length of the beam bottom bars in the joint area. By applying half of the demand ductility of the primary direction in the orthogonal direction, the seismic performance of the frame in the primary direction changes due to the entry of the corner joint area space into bidirectional interactions. On average, in the joints under the studied joints under limited bidirectional loading, the maximum force that can be tolerated by the specimen is reduced by 10% compared to the unidirectional loading. If the bidirectional loading is applied in equal proportions in two orthogonal directions, not only does it reduce the force capacity of the corner joints by an average of 32%, but also the initial stiffness of the specimen, the effective stiffness in drift by 1.75%, the energy dissipation capacity and the ductility are reduced by 54%, 40%, 35% and 23%, respectively, compared to the unidirectional loading condition.

Keywords

Beam-Column Joints; Reinforced Concrete Structures; Bidirectional Lateral Loading; Corner Joint; Experimental Evaluation

References

[1] D. Guan, C. Jiang, Z. Guo and H. Ge, “Development and seismic behavior of precast concrete beam-to-column connections,” Earthquake Engineering, vol. 22, no. 2, pp. 234-256, 2018. https://doi.org/10.1080/13632469.2016.1217807

[2] S. A.  Nezami and J. Shafaei, “Analytical modeling of rehabilitated beam-column connections with non-seismic details using joint enlargement and post-tensioned,” Civil and Environmental Engineering, vol. 54, no. 117, pp. 37-53, 2025. https://doi.org/10.22034/CEEJ.2024.58965.2298

[3] S. A.  Nezami and J. Shafaei, “Non-linear strut and tie modelling approach of retrofitted reinforced concrete beam column joint by prestress joint enlargement,” Ferdowsi Civil Engineering, vol. 37, no. 3, pp. 13-40, 2024. https://doi.org/10.22067/jfcei.2024.85341.1271

[4] N. D. Hadi, N. H. A. Hamid, I. F. Azmi, R. Hassan, Y. Sutopo, B. Chao and N. A. Zainuddin, “Comparison of seismic response corner beam-column joint with and without fuse bars under in-plane lateral cyclic loading,” Solids and Structures, vol. 19, no. 1, 2022. https://doi.org/10.1590/1679-78256581

[5] J. Shafaei and S. A. Nezami, “Effect of different size of joint enlargement on seismic behavior of gravity load designed RC beam‐column connections,” The Structural Design of Tall and Special Buildings, vol. 28, no. 14, pp. 1653-1680, 2019. https://doi.org/10.1002/tal.1653

[6] V. Mahadik and A. Sharma, “Bidirectional loading history for seismic testing of 3D frame joints,” CivilEng, vol. 2, no. 2, pp. 349-369, 2021. https://doi.org/10.3390/civileng2020019

[7] K. Kitayama and H. Katae, “Earthquake resistance of reinforced concrete corner beam-column joints with different column axial loads under bi-directional lateral loading,” Bulletin of the New Zealand Society for Earthquake Engineering, vol. 50, no. 4, pp. 527-536, 2017. https://doi.org/10.5459/bnzsee.50.4.527-536

[8] S. Park and K. M. Mosalam, “Experimental investigation of nonductile RC corner beam-column joints with floor slabs,” Structural Engineering, vo. 139, no. 1, pp. 1-14, 2013. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000591

[9] I. Topcu, “Experimental research on seismic retrofitting of R/C corner beam-column-slab joints upgraded with CFRP sheets,” M.S. thesis, Bogaziçi University, İstanbul, Turkey, 2008.

[10] V. M. Sanchez, B. Lloyd, W. M. Hassan and J. P. Moehle, “Evaluation of non-ductile reinforced concrete building corner joint experiencing early column failure,” presented at Pacific Earthquake Engineering Centre, University of California, Berkeley, 2009.

[11] D. Mostofinejad and M. Hajrasouliha, “3D beam-column corner joints retrofitted with X-shaped FRP sheets attached via the EBROG technique,” Engineering Structures, vol. 183, no. 1, pp. 987-998, 2019. https://doi.org/10.1016/j.engstruct.2019.01.038

[12] M. Hajrasouliha and D. Mostofinejad, “Effect of lateral beam on the seismic behavior of corner RC beam-column joints under cyclic reversal loading,” Environmental and Civil Engineering, vol. 25, no. 12, pp. 2146-2160, 2019. https://doi.org/10.1080/19648189.2019.1618738

[13] S. Fayed, A. G. Asran and H. H. El-Esnawi, “An experimental and numerical study on behaviour of reinforced concrete corner beam-column joint,” Innovative Infrastructure Solutions, vol. 8, no. 41, pp. 64-92, 2023. https://doi.org/10.1007/s41062-022-01000-w

[14] A. M. Basha and S. Fayed, “Behavior of RC eccentric corner beam-column joint under cyclic loading: An experimental work,” Civil Engineering, vol. 5, no. 2, pp. 295-308, 2019. http://dx.doi.org/10.28991/cej-2019-03091245

[15] S. W. Han and C. S. Lee, “Cyclic behavior of RC OMF beam-corner column joints under unidirectional and bidirectional loadings,” Engineering Structures, vol. 224, pp. 111-123, 2020. https://doi.org/10.1016/j.engstruct.2020.111304

[16] A. Marchisella and G. Muciaccia, “Bi–axially loaded RC beam–column joints and haunch retrofit,” Bulletin of Earthquake Engineering, vol. 22, no. 6, pp. 3125-3167, 2024. https://doi.org/10.1007/s10518-024-01881-5

[17] R. Park and T. Paulay, Reinforced concrete structures. John Wiley & Sons New York, 1991.

[18] W.M. Hassan and J. P. Moehle, “Experimental assessment of seismic vulnerability of corner beam-column joints in older concrete buildings,” In  Proceedings 15^th World Conference Earthquake Eng, Lisbon, Portugal, 2012.

[19] M.S. Marefat, M. Khanmohammadi, M.K. Bahrani and A. Goli, “Experimental assessment of reinforced concrete columns with deficient seismic details under cyclic load”, Advances in Structural Engineering, vol. 9, no. 3, pp. 337-347, 2006. https://doi.org/10.1260/136943306777641959

[20] ACI Committee 318-19, Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19). American Concrete Institute, Farmington Hills, Michigan, USA, 2019.

[21] ACI-374.1-05, Acceptance criteria for moment frames based on structural testing and commentary. American Concrete Institute, Farmington Hills, Michigan, USA, 2005.

[22] Y.J. Park and A.H. Ang, “Mechanistic seismic damage model for reinforced concrete,” Journal of Structural Engineering, vol. 111, no. 4, pp. 722-739, 1985. https://doi.org/10.1061/(ASCE)0733-9445(1985)111:4(722)