Combined bending and torsion behavior of externally strengthened RC beams via enlargement section and hybrid reinforcement

Hamza, Abrar Raheem; Al-Khekany, Alaa M.; Bal´azs, Gy¨orgy L.

doi:10.30772/qjes.2024.148224.1174

	Combined bending and torsion behavior of externally strengthened RC beams via enlargement section and hybrid reinforcement
Al-Qadisiyah Journal for Engineering Sciences
Volume 18, Issue 4, December 2025, Pages 465-474 PDF (7.92 M)
Document Type: Research Paper
DOI: 10.30772/qjes.2024.148224.1174
Authors
Abrar Raheem Hamza¹^{, 2}; Alaa M. Al-Khekany¹; Gy¨orgy L. Bal´azs³
¹Department of Civil Engineering, College of Engineering, University of Al-Qadisiyah, Qadisiyah, Iraq.
²Ministry of Education, General Directorate of Education of Qadisiyah, Qadisiyah, Iraq.
³Department of Construction Materials and Technologies, Faculty of Civil Engineering, Budapest University of Technology and Economics, Budapest, Hungary.
Abstract
The research uses self-consolidating concrete (SCC) reinforced with steel bars, glass fiber reinforced polymer (GFRP), or hybrid reinforcement to improve the torsional capacity of reinforced concrete (RC) structures. Nine beams are cast in normal strength concrete (NSC), and eight are strengthened with steel, GFRP, and hybrid reinforcing bars for the pilot program. The examples are categorized by reinforcing layer thickness (Δh = 50mm and Δh = 75mm) and total depth (325 and 350mm) with a 25mm concrete cover. A control beam was examined for comparison, along with eight reinforced beams of various thicknesses. The tests focus on the impact of raising the Δh value, which increases effective depth, and the GFRP replacement ratio (0% to 100%). All beam specimens were torsional-loaded till failure. Increasing the thickness of RC beams reinforced with steel, GFRP, or hybrid bars (steel and GFRP) to ∆ = 50 mm significantly improved their ultimate torsional capacity. RC ranges rose from 33.33% to 66.67% over the control sample. The ultimate torsional capacity of the reinforced beams, at thickness ∆h = 75 mm, improved from 60% to 100% relative to the control sample.
Keywords
Concrete jacket; GFRP bar; hybrid reinforce; Section enlargement; Torsional strength

References
Jariwala, P. Patel, and S. Purohit, “Strengthening of rc beams subjected to combined torsion and bending with gfrp composites,” Procedia Engineering, vol. 51, pp. 282–289, 2013. [Online]. Available: https://doi.org/10.1016/j.proeng.2013.01.038 Park and T. Paulay, Reinforced Concrete Structures. John Wiley Sons, Ltd, 1975, pp. i–xvii. [Online]. Available: https://doi.org/10.1002/9780470172834.fmatter Aziz and O. Hashim, “Torsional strength evaluation of reinforced scc box beams strengthened internally by opened and closed transverse concrete diaphragms,” MATEC Web Conf., vol. 162, no. 04009, p. 9, 2018. [Online]. Available: https://doi.org/10.1051/matecconf/201816204009 Naderpour, O. Poursaeidi, and M. Ahmadi, “Shear resistance prediction of concrete beams reinforced by frp bars using artificial neural networks,” Measurement, vol. 126, pp. 299–308, 2018. [Online]. Available: https://doi.org/10.1016/j.measurement.2018.05.051 S. Al-Yassri, A.Y. Ali, and M. M. AL-Khafaji, “Experimental investigation for the behavior of hollowcore concrete slab reinforced with hybrid reinforcement,” Al-Qadisiyah Journal for Engineering Sciences, vol. 10, no. 3, pp. 308–317, 2017. [Online]. Available: https://qjes.qu.edu.iq/article 131619.html Xue, F. Peng, and Q. Zheng, “Design equations for flexural capacity of concrete beams reinforced with glass fiber–reinforced polymer bars,” Journal of Composites for Construction, vol. 20, no. 3, p. 04015069, 2016. [Online]. Available: https://doi.org/10.1061/(ASCE)CC.1943-5614.0000630 Qu, X. Zhang, and H. Huang, “Flexural behavior of concrete beams reinforced with hybrid (gfrp and steel) bars,” Journal of Composites for construction, vol. 13, no. 5, pp. 350–359, 2009. [Online]. Available: https://doi.org/10.1061/(ASCE)CC.1943-5614.0000035 Acciai, A. D’Ambrisi, M. De Stefano, F. F. Feo, L., and R. Nudo, “Experimental response of frp reinforced members without transverse reinforcement: Failure modes and design issues,” Composites Part B: Engineering, vol. 89, pp. 397–407, 2016. [Online]. Available: https://doi.org/10.1016/j.compositesb.2016.01.002 N. Rahal, “Torsional strength of reinforced concrete beams,” Canadian Journal of Civil Engineering, vol. 27, no. 3, pp. 445–453, 2000. [Online]. Available: https://doi.org/10.1139/l99-083 M. Gajipara, P. V. Patel, and S. D. Raiyani, “Behavior of rc hollow beam under pure cyclic torsion,” Int J Res in Eng. Technol., vol. 04, no. 13, pp. 407–412,2015. [Online]. Available: https://ijret.org/volumes/2015v04/i25/IJRET20150425060.pdf B. Tibhe and V. R. Rathi, “Comparative experimental study on torsional behavior of rc beam using cfrp and gfrp fabric wrapping,” Procedia Technology, vol. 24, pp. 140–147, 2016. [Online]. Available: https://doi.org/10.1016/j.protcy.2016.05.020 E. Salama, M. E. Kassem, and A. A. Mahmoud, “Torsional behavior of t-shaped reinforced concrete beams with large web openings,” Journal of Building Engineering, vol. 18, pp. 84–94, 2018. [Online]. Available: https://doi.org/10.1016/j.jobe.2018.02.004 C. Al-Ziady and H. Al-Thairy, “Torsional behaviour of rc beams strengthened by nsm gfrp bars,” In IOP Conference Series: Earth and Environmental Science, vol. 1232, no. 1, p. 012037, 2023. [Online]. Available: https://doi.org/10.1088/1755-1315/1232/1/012037 Alzabidi, G. Diaa, A. Abadel, K. Sennah, and H. Abdalla, “Rehabilitation of reinforced concrete beams subjected to torsional load using ferrocement,” Case Studies in Construction Materials, vol. 19, no. 4, p. e02433, 2023. [Online]. Available: https://doi.org/10.1016/j.cscm.2023.e02433 Committee, “318-19 building code requirements for structural concrete and commentary,” ACI, 2019. [Online]. Available: https://api.semanticscholar.org/CorpusID:243163499 Shokri, M. Edalati, S. Mirhosseini, and E. Zeighami, “Fe analysis on size effect in torsional behavior of rectangular rc beams with and without frp strengthening,” KSCE Journal of Civil Engineering, vol. 28, no. 5, pp. 1836–1852, 2024. [Online]. Available: https://doi.org/10.1007/s12205-024-0020-0 ELWakkad, K. Heiza, and W. Mansour, “Experimental study and finite element modelling of the torsional behavior of self-compacting reinforced concrete (scrc) beams strengthened by gfrp,” Case Studies in Construction Materials, vol. 18, p. e02123, 2023. [Online]. Available: https://doi.org/10.1016/j.cscm.2023.e02123 Karimipour, J. De Brito, M. Ghalehnovi, and O. Gencel, “Torsional behaviour of rectangular high-performance fibre-reinforced concrete beams,” Structures, vol. 35, pp. 511–519, 2022. [Online]. Available: https://doi.org/10.1016/j.istruc.2021.11.037 El-Mandouh, J. Hu, W. Shim, F. Abdelazeem, and G. ELsamak, “Torsional improvement of rc beams using various strengthening systems,” Buildings, vol. 12, no. 11, p. 1776, 2022. [Online]. Available: https://doi.org/10.3390/buildings12111776 MA and M. MN., “Strengthening reinforced beams subjected to pure torsion by near surface mounted rebars,” Anbar Journal for Engineering Sciences., vol. 13, no. 1, pp. 13–22, 2022. [Online]. Available: https://doi.org/10.37649/aengs.2022.175876 “Iraqi standard specification (iqs) no.5.for portland cement central organization for standardization and quality,” 2019. [Online]. Available: https://iraqi-standards.org/Home/Ssection “Iraq standard specification (iqs) no.45 natural sources of aggregate used in building and concrete, baghdad, 13p.” 2019. [Online]. Available: https://iraqi-standards.org/Home/Ssection Group, “The european guidelines for self compacting concrete represent a state-of-the-art document addressed to specifiers, designers, purchasers, producers and users who wish to enhance their expertise and use of scc,” European Guidelines for Self Compacting Concrete (SCC), 2005. [Online]. Available: efnarc.org ASTM-A615/A615M-09b, “Standard specification for deformed and plain carbon-steel bars for concrete reinforcement,” 2009. [Online]. Available: https://doi.org/10.1520/A0615 A0615M-09B S. Abo Dhaheer, M. M. Al-Rubaye, W. S. Alyhya, B. L. Karihaloo, and S. Kulasegaram, “Proportioning of self–compacting concrete mixes based on target plastic viscosity and compressive strength: part i-mix design procedure.” Journal of Sustainable Cement-Based Materials, vol. 5, no. 4, pp. 199–216, 2016. [Online]. Available: https://doi.org/10.1080/21650373.2015.1039625 S. e. a. Alyhya, “A rational method for the design of self-compacting concrete mixes based on target plastic viscosity and compressive strength,” Aberdeen, UK,35th Cement concrete science conference (CCSC35, p. 85–9, 2015. [Online]. Available: https://doi.org/10.1088/1757-899X/671/1/012117 Solikin, Basuki, and B. Setiawan, “The utilization of self compacting concrete (scc) in producing hollow concrete panel wall to provide rapid shelter for post disaster area,” Procedia Engineering, vol. 54, pp. 742–751, 2013, the 2nd International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE). [Online]. Available: https://doi.org/10.1016/j.proeng.2013.03.068 H. Jariwala, P. V. Patel, and S. P. Purohit, “Strengthening of rc beams subjected to combined torsion and bending with gfrp composites,” Procedia Engineering, vol. 51, pp. 282–289, 2013, chemical, Civil and Mechanical Engineering Tracks of 3rd Nirma University International Conference on Engineering (NUiCONE2012). [Online]. Available: https://doi.org/10.1016/j.proeng.2013.01.038
Statistics Article View: 222 PDF Download: 146