Experimental Study of Seismic Behavior and Modification of the Failure Region of Mechanical Bar Splices

Document Type : Research Note

Authors

1 Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 International Institute of Earthquake Engineering and Seismology, Tehran, Iran

Abstract

The problem of overcrowding at the junction of the rebars is very significant, particularly for seismic details. Due to bar length limits, splicing of reinforcing bars is unavoidable in reinforced concrete (RC) structures and may alter the overall behavior of structures under static and dynamic stresses. Mechanical couplers can thus offer an appealing solution that eliminates the disadvantages of traditional reinforcement splicing. In the mechanical splice method, couplers are rigid components that are used to join reinforcement bars together. According to existing research, the failure mechanism of a thread splice under tensile and cyclic loads has not been sufficiently investigated. In addition, the use of the thread splice needs further investigation in the plastic hinge areas of ductile members in seismic areas. In this study, two types of patches are introduced by modifying the method of making a threaded splice and combining it with rotary friction welding. The goal is to modify the coupler's failure area with a threaded bar and use it in the plastic hinge areas of ductile members in seismic areas. The splice area in the suggested method is large. Two techniques are used to increase the splice area: cold rolling and rotating friction welding. In total, 96 samples were tested (three repeated samples of each type). Threaded couplers (TC), oversized-threaded couplers (OTC), rotary friction welding splices with threaded couplers (RFWTC), and non-spliced (NS) reference specimens were tested with and without concrete in uniaxial tensile and cyclic tests. Evaluations were conducted on the sensitivity to bar diameter, bar strength, ductility, energy absorption, and failure mode performance. The RFWTC and OTC exhibited superior performance in terms of strength, ductility, energy absorption, and failure mode, making them appropriate for use in high seismic zones. The TC is also suitable for use in zones with low to medium seismic activity. Furthermore, the anticipated model is enough for estimating the threaded couplers' ultimate tensile strength.

Keywords

Main Subjects


 1. Abé, M. and Shimamura, M., 2014. Performance of railway bridges during the 2011 Tōhoku earthquake. of Performance of Constructed Facilities, 28(1), pp.13–23. DOI:10.1061/(ASCE)CF.1943-5509.0000379.
2. ICC Evaluation Service, LLC (ICC-ES), (n.d.). AC133 - Acceptance Criteria. Available at: https://icc-es.org/acceptance-criteria/ac133/ (Accessed: 13 December 2022).
3. ACI Committee 318, 2019. 318-19 Building Code Requirements for Structural Concrete and Commentary. American Concrete Institute. DOI:10.14359/51716937.
4. ACI Committee 318, 2019. Building Code Requirements for Structural Concrete (ACI 318-19). American Concrete Institute.
5. ACI Committee 439, 2007. Types of Mechanical Splices for Reinforcing Bars. American Concrete Institute.
6. Al-Jelawy, H. M., 2022. Experimental and numerical investigations on monotonic tensile behavior of grouted sleeve couplers with different splicing configurations. Engineering Structures, 265, 114434. https://DOI:10.1016/j.engstruct.2022.114434.
7. ASTM International, (n.d.). ASTM E8 / E8M - 16ae1 Standard Test Methods for Tension Testing of Metallic Materials. Available at: https://www.astm.org/Standards/E8 (Accessed: 19 October 2020).
8. Bai, A. S. H. and Ingham, J. M., 2009. Seismic performance of mechanically coupled reinforcing bars. Magazine of Concrete Research, 61(7), pp.529–537. DOI:10.1680/macr.2008.00098.
9. Bompa, D. V. and Elghazouli, A. Y., 2017. Ductility considerations for mechanical reinforcement couplers. Structures. https://DOI:10.1016/j.istruc.2017.08.007.
10. Bompa, D. V. and Elghazouli, A. Y., 2018. Monotonic and cyclic performance of threaded reinforcement splices. Structures, 16, pp. 358–372. https://DOI:10.1016/j.istruc.2018.11.009.
11. Bompa, D. V. and Elghazouli, A. Y., 2019. Inelastic cyclic behaviour of RC members incorporating threaded reinforcement couplers. Engineering Structures, 180, pp. 468–483. https://DOI:10.1016/j.engstruct.2018.11.053.
12. British Standards Institution, 2004. Eurocode 2: Design of Concrete Structures: Part 1-1: General Rules and Rules for Buildings. British Standards Institution.
13. Çelik, S. and Ersozlu, I., 2014. Investigation of microstructure and mechanical properties of friction welded AISI 316 and CK 45 steels. High Temperature Materials and Processes. DOI:10.1515/htmp-2013-0042.
14. Dabiri, H., Kheyroddin, A. and Faramarzi, A., 2022. Predicting tensile strength of spliced and non-spliced steel bars using machine learning- and regression-based methods. Construction and Building Materials. https://DOI:10.1016/j.conbuildmat.2022.126835.
15. Dahal, P. K. and Tazarv, M., 2020. Mechanical bar splices for incorporation in plastic hinge regions of RC members. Construction and Building Materials, 258, 120308. https://DOI:10.1016/j.conbuildmat.2020.120308
16. Einea, A., Yehia, S. and Tadros, M. K., 1999. Lap splices in confined concrete. ACI Structural Journal, 96(6), pp. 947–955. DOI:10.14359/769.
17. Emre, H. E. and Kaçar, R., 2015. Effect of post-weld heat treatment process on microstructure and mechanical properties of friction welded dissimilar drill pipe. Materials Research. DOI:10.1590/1516-1439.308114.
18. European Committee for Standardization, 2004. Eurocode 8: Design of Structures for Earthquake Resistance - Part 1: General Rules, Seismic Actions and Rules for Buildings. European Committee for Standardization.
19. Ghayeb, H. H., Abdul Razak, H., Ramli Sulong, N. H., Mo, K. H., Abutaha, F. and Gordan, M., 2021., 2021. Performance of mechanical steel bar splices using grouted couplers under uniaxial tension. of Building Engineering. https://DOI:10.1016/j.jobe.2020.101892.
20. Harinkhede, S. and Varghese, V., 2021. Investigation on design of new techniques in mechanical rebar coupler as an alternative to lap splices. In Lecture Notes in Mechanical Engineering, Springer, Singapore, pp. 57–61. DOI:10.1007/978-981-15-8025-3_7.
21. Hassan, T. K., Lucier, G. W. and Rizkalla, S. H., 2012. Splice strength of large diameter, high strength steel reinforcing bars. Construction and Building Materials. https://DOI:10.1016/j.conbuildmat.2011.06.013.
22. Henin, E. and Morcous, G., 2015. Non-proprietary bar splice sleeve for precast concrete construction. Engineering Structures, 83, pp. 154–162. https://DOI:10.1016/j.engstruct.2014.10.045.
23. Hulshizer, A. J., Ucciferro, J. J. and Gray, G. E., 1994. Mechanical reinforcement couplings meet demands of strength and constructibility. Concrete International, 16(12), pp. 47–52.
24. ISO/DIS 15835, 2018. Steel for the Reinforcement of Concrete - Reinforcement Couplers for Mechanical Splices of Bars (Parts 1 to 3). International Organization for Standardization, Geneva, Switzerland.
25. Kheyroddin, A. and Dabiri, H., 2020. Cyclic performance of RC beam-column joints with mechanical or forging (GPW) splices; an experimental study. Structures. https://DOI:10.1016/j.istruc.2020.10.071.
26. Kuscu, H., Becenen, I. and Sahin, M., 2008. Evaluation of temperature and properties at the interface of AISI 1040 steels joined by friction welding. Assembly Automation. DOI:10.1108/01445150810904468.
27. Lee, C. S. and Han, S. W., 2019. Cyclic behaviour of lightly-reinforced concrete columns with short lap splices subjected to unidirectional and bidirectional loadings. Engineering Structures. https://DOI:10.1016/j.engstruct.2019.03.108.
28. Li, W. and Wang, F., 2011. Modeling of continuous drive friction welding of mild steel. Materials Science and Engineering A. https://DOI:10.1016/j.msea.2011.04.001.
29. Liu, C., Pan, L., Liu, H., Tong, H., Yang, Y. and Chen, W., 2020. Experimental and numerical investigation on mechanical properties of grouted-sleeve splices. Construction and Building Materials. https://DOI:10.1016/j.conbuildmat.2020.120441.
30. Maalekian, M., 2007. Friction welding - Critical assessment of literature. Science and Technology of Welding and Joining. DOI:10.1179/174329307X249333.
31. Najafgholipour, M. A., Dehghan, S. M., Khani, M. and Heidari, A., 2018. The performance of lap splices in RC beams under inelastic reversed cyclic loading. Structures. https://DOI:10.1016/j.istruc.2018.07.011
32. Nateghi-Alahi, F. and Shokrzadeh, M. R., 2019. Behavior considerations for mechanical rebar couplers. In Behavior Considerations for Mechanical Rebar Couplers. University of Tokyo, pp. 30–41. Available at: https://isn.ac/XBHB-EZGFF.
33. Saito, T., Yabe, Y. and Fujimori, T., 1985. An ultrasonic testing method for gas pressure welded joints of reinforcing steel bars. https://DOI:10.1016/0041-624X(85)90060-5.
34. Seshu Kumar, A., Khadeer, S. A., Rajinikanth, V., Pahari, S. and Ravi Kumar, B., 2021. Evaluation of bond interface characteristics of rotary friction welded carbon steel to low alloy steel pipe joints. Materials Science and Engineering https://DOI:10.1016/j.msea.2021.141844.
35. Sharbatdar, M. K., Jafaria, O. M. and Karimib, M. S., 2018. Experimental evaluation of splicing of longitudinal bars with forging welding in flexural reinforced concrete beams. Advances in Concrete Construction. DOI:10.12989/acc.2018.6.5.509.
36. Shokrzadeh, M. R., Aziminejhad, A. and Sarvghadmoghaddam, A., 2016. Hysteretic behavior of concrete connections strengthened by X-shape FRP strips. Analysis of Structure and Earthquake, 12(4), pp. 29–40. Available at: https://civil-strj.maragheh.iau.ir/article_525485.html (Accessed: 8 November 2016). [In Persian].
37. Shokrzadeh, M. R., Nateghi-E, Mansoori, M. R. and Javadi, P., 2022. Failure area evaluation of the coupler with threaded bar: Experimental and numerical study. J. of Advanced Structural Engineering, 12(1), pp. 531–543. DOI:10.1007/ijase.2022.692294.
38. Shokrzadeh, M. R., Nateghi-E, Mansoori, M. R. and Javadi, P., 2023. The improvement of the threaded-based mechanical splice by modifying the threaded system: Study of techniques cold rolling and rotating friction welding. J. of Building Engineering, 80, 107964. https://DOI:10.1016/j.jobe.2023.107964.
39. Shokrzadeh, M. R., 2024. Experimental study of seismic behavior and modification of the failure region of mechanical bar splices in reinforced concrete vertical elements. Islamic Azad University Science and Research Branch, pp. 175–488. DOI:10.32432/brs-290180.
40. Shokrzadeh, M. R. and Nateghi-Alahi, F., 2022. Evaluation of hybrid NSM-CFRP technical bars and FRP sheets for seismic rehabilitation of a concrete bridge pier. Bridge Structures, 18(3–4), pp. 75–88. DOI:10.3233/brs-290180.
41. Structural Engineering Lab - International Institute of Earthquake Engineering and Seismology, (n.d.). Available at: http://www.iiees.ac.ir/en/structural-laboratory/ (Accessed: 28 November 2021).
42. Tazarv, M., LaVoy, M., Sjurseth, T., Greeneway, E. and Wehbe, N., 2023. Analysis and design of mechanically spliced precast bridge columns. Engineering Structures, 280, 115726. https://DOI:10.1016/j.engstruct.2023.115726.
43. Tazarv, M. and Saiidi, M. S., 2016. Seismic design of bridge columns incorporating mechanical bar splices in plastic hinge regions. Engineering Structures. https://DOI:10.1016/j.engstruct.2016.06.041.
44. Tazarv, M., Shrestha, G. and Saiidi, M. S., 2021. State-of-the-art review and design of grouted duct connections for precast bridge columns. Structures. https://DOI:10.1016/j.istruc.2020.12.091.
45. Woodhead Publishing Series in Welding and Other Joining Technologies, 2014. In Control of Welding Distortion in Thin-Plate Fabrication. DOI:10.1016/b978-0-85709-047-8.50016-9.
46. Yamamoto, R. I., Fukada, Y., Tatsumi, M. and Ueyama, K., 2002. New quality inspection method for gas pressure welds. Quarterly Report of RTRI (Railway Technical Research Institute) (Japan). DOI:10.2219/rtriqr.43.7.
47. Yilmaz, M., Kaluc, E., Tülbentci, K. and Karagöz, S., 1996. Investigation into the weld zone of friction welded C45/HS6-5-2 dissimilar steel joints. of Materials Science Letters. DOI:10.1007/BF00591663.
48. Zhao, E., Song, C., Zhang, X., Zhou, Q. and Yan, K., 2022. Experimental study on monotonic, cyclic mechanics and fatigue performance of pressed cone sleeve splices. Structures. https://DOI:10.1016/j.istruc.2022.03.050.