Document Type : Review Paper

Authors

Civil Engineering Dept., University of Technology-Iraq, Alsina’a street, 10066 Baghdad, Iraq.

Abstract

Reinforced concrete beams are the most generally used structural parts in building, bridges, and many other structures. In the past two decades, many investigations have been conducted using various fiber-reinforced polymer (FRP) material types /steel bars to reinforce concrete beams under flexural test. The purpose of this paper is to review the flexural performance of concrete beams reinforced with hybrid FRP and steel bars to better understand their behavior. The main parameters addressed by researchers were dimensions of beams, FRP bar material type, and hybrid reinforcement ratio. The researchers established that the use of the combination between steel and FRP reinforcement bars improves the performance of the concrete beams. Moreover, the studies showed that the ductility of the hybrid reinforced beams increased compared to that of conventional steel reinforced beams, however, it decreased when the ratio of (Af/As) increased. The application of using hybrid FRP/steel bars in reinforcing concrete beams will further increase upon utilizing techniques for reducing the brittleness and higher cost of FRP bars. The general structure of this paper consists of presenting the formulas offered by ACI 440.1R-15 building code relating to the flexural strength calculation of concrete beams reinforced with FRP/steel bars. The paper also details some of the current experimental tests and analytical works published for concrete beams reinforced with hybrid system, and outlines research directions and identifies gaps required for additional research.

Graphical Abstract

Highlights

  • Using hybrid FRP/ steel bars in reinforcing concrete beams demonstrated better flexural performance.
  • Existing design method for reinforced concrete beams with hybrid reinforcements is reviewed.
  •  Experimental and analytical studies regarding hybrid reinforced concrete beams are presented.
  • Further research directions are proposed to better understand the effect of many parameters on the flexural capacity.  

Keywords

Main Subjects

[1] H. M. Mohamed and B. Benmokrane, Design and performance of reinforced concrete water chlorination tank totally reinforced with GFRP bars: Case study, J. Compos. Constr., 18(2014) 05013001. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000429
[2] Z. Wang, X. Zhao, G. Xian, G. Wu, R. Singh Raman, S. Al-Saadi, and A. Haque, Long-term durability of basalt-and glass-fibre reinforced polymer (BFRP/GFRP) bars in seawater and sea sand concrete environment, Constr. Build. Mater.,  139(2017) 67–489.
[3] H. Shaowei, C. Qiyong, and G. Nina, Effect of acid corrosion on crack propagation of concrete beams, Sādhanā, 43, (2018)1–13.
[4] G. Xu, L. Liu, H. Bao, Q. Wang, and J. Zhao, Mechanical properties of steel corrosion products in reinforced concrete, Mater. Struct., 50(2017) 1–10.
[5] A. I. A.-D. Abd El Fattah, K. Riding, and M. Thomas, Field evaluation of corrosion mitigation on reinforced concrete in marine exposure conditions, Constr. Build. Mater., 165(2018) 663–674.
[6] Y. Tang and Z. Wu, Distributed long-gauge optical fiber sensors based self-sensing FRP bar for concrete structure, Sensors (Switzerland), 16 (2016). https://doi.doi: 10.3390/s16030286.
[7] C. Jiang, Y.-F. Wu, and M.-J. Dai, Degradation of steel-to-concrete bond due to corrosion, Constr. Build. Mater.,  158 (2018)1073–1080.
[8] P. E. Team, FRP Rebar (AFRP, CFRP, GFRP). Purdue University,  1–6, 2007. https://doi.10.5703/1288284315719.
[9] H. N. Garden and L. C. Hollaway, An experimental study of the influence of plate end anchorage of carbon fibre composite plates used to strengthen reinforced concrete beams, Compos. Struct.,  42(1998) 175–188. https://doi.org/10.1016/S0263-8223(98)00070-1
[10] L. C. Hollaway, Hollaway, L. C. (2010). A review of the present and future utilisation of FRP composites in the civil infrastructure with reference to their important in-service properties, Constr. Build. Mater., 24 (2010) 2419–2445.
[11] ACI440.2R-08, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. Technical Documents. 2008.
[12] A. A. K. Sharba, H. D. Hussain, and M. Abdulhussain, Retrofitting of RC beams using FRP techniques: a review, in In IOP Conference Series: Materials Science and Engineering,  1090 (2021) 012054.
[13] H. Zhu, C. Li, S. Cheng, and J. Yuan, Flexural Performance of Concrete Beams Reinforced with Continuous FRP Bars and Discrete Steel Fibers under Cyclic Loads, Polymers,  14 (2022) 1399. https://doi.10.3390/polym14071399.
[14] X. Fan and M. Zhang, Experimental study on flexural behaviour of inorganic polymer concrete beams reinforced with basalt rebar, Compos. Part B Eng., 93 (2016) 174–183. https://doi.org/10.1016/j.compositesb.2016.03.021
[15] O. A. Mohamed, W. Al Hawat, and M. Keshawarz, Durability and mechanical properties of concrete reinforced with basalt fiber-reinforced polymer (Bfrp) bars: Towards sustainable infrastructure, Polymers, 13 (2021). https://doi.10.3390/polym13091402.
[16] A. Richardson and P. Drew, Fibre reinforced polymer and steel rebar comparative performance, Struct. Surv., 29(011) 63–74. https://doi.10.1108/02630801111118412
[17] A. Cripps, B. Harris, and T. Ibell, Fibre-reinforced polymer composites in construction, Ciria, 2002.
[18] H. Ashrafi, M. Bazli, and N. A. V. O. Esmaeil Pournamazian, The effect of mechanical and thermal properties of FRP bars on their tensile performance under elevated temperatures, Constr. Build. Mater., 157(2017) 1001–1010.
[19] D. G. Goodwin, S. Sattar, J. D. Dukes, J. H. Kim, L. P. Sung, and C. C. Ferraris, Research Needs Concerning the Performance of Fiber Reinforced (FR) Composites Retrofit Systems for Buildings and Infrastructure, Special Publication (NIST SP) - 1244. 2019.
[20] C. Bakis, E. Lawrence, C. Bank, V. Brown, E. Cosenza, J. F. Davalos, J. J. Lesko, A. Machida, S. H. Rizkalla, and T. C. Triantafillou, Fiber-reinforced polymer composites for construction—State-of-the-art review, J. Compos. Constr., 6, (2002) 73–87.https://doi.org/10.1061/(ASCE)1090-0268(2002)6:2(73)
[21] S. Kim and S. Kim, Flexural behavior of concrete beams with steel bar and FRP reinforcement, J. Asian Archit. Build. Eng., 18 (2019) 94–102. https://doi.10.1080/13467581.2019.1596814.
[22] A. F. Ashour, Flexural and shear capacities of concrete beams reinforced with GFRP bars, Constr. Build. Mater., 20 (2006) 1005–1015.
[23] I. S. Abbood, S. A. Odaa, K. F. Hasan, and M. A. Jasim, Properties evaluation of fiber reinforced polymers and their constituent materials used in structures - A review, Mater. Today Proc., 43 (2021) 1003–1008. https://doi.10.1016/j.matpr.2020.07.636.
[24] H. Zhu, Z. Li, C. Wen, S. Cheng, and Y. Wei, Prediction model for the flexural strength of steel fiber reinforced concrete beams with fiber-reinforced polymer bars under repeated loading, Compos. Struct., 250 (2020) 112609. https://doi.10.1016/j.compstruct.2020.112609
[25] Z. Sun, L. Fu, D. C. Feng, A. R. Vatuloka, Y. Wei, and G. Wu, Experimental study on the flexural behavior of concrete beams reinforced with bundled hybrid steel/FRP bars, Eng. Struct.,  (2019) 197. https://doi.10.1016/j.engstruct.2019.109443
[26] H. G. Harris, W. Somboonsong, and F. K. Ko, New ductile hybrid FRP reinforcing bar for concrete structures, J. Compos. Constr., 2(1998) 28–37. https://doi.org/10.1061/(ASCE)1090-0268(1998)2:1(28)
[27] R. Qin, A. Zhou, and D. Lau, Effect of reinforcement ratio on the flexural performance of hybrid FRP reinforced concrete beams, Composites Part B: Engineering, 108 (2017)  200–209. https://doi.org/10.1016/j.compositesb.2016.09.054
[28] C. Arya, F. Ofori-Darko, and G. Pirathapan, 27 FRP Rebars and The Elimination of Reinforcement Corrosion in Concrete Structures. in Non-Metallic (FRP) Reinforcement for Concrete Structures, in Proceedings of the Second International RILEM Symposium, 1995.
[29] A. El Refai, F. Abed, and A. Al-Rahmani, Structural performance and serviceability of concrete beams reinforced with hybrid (GFRP and steel) bars, Constr. Build. Mater., 96 (2015) 18–529. https://doi.10.1016/j.conbuildmat.2015.08.063.
[30] ACI Committee 440, ACI440.1R-15 Guide for the Design and Construction of Structural Concrete Reinforced with Firber-Reinforced Polymer (FRP) Bars, 22, 2015.
[31] W. Qu, X. Zhang, and H. Huang, Flexural Behavior of Concrete Beams Reinforced with Hybrid (GFRP and Steel) Bars, J. Compos. Constr.,  13 (2009) 350–359. https://doi.10.1109/MACE.2010.5536776.
[32] L. Pang, W. J. Qu, P. Zhu, and J. J. Xu, Design propositions for hybrid FRP-steel reinforced concrete beams, J. Compos. Constr., 20 (2016) 04015086.
[33] P. Preinstorfer, T. Huber, S. Reichenbach, J. M. Lees, and B. Kromoser, Parametric Design Studies of Mass-Related Global Warming Potential and Construction Costs of FRP-Reinforced Concrete Infrastructure, Polymers, 14 (2022)  2383. https://doi.10.3390/polym14122383.
[34] F. Bencardino, A. Condello, and L. Ombres, Numerical and analytical modeling of concrete beams with steel, FRP and hybrid FRP-steel reinforcements, Compos. Struct.,140 (2016) 53–65. https://doi.10.1016/j.compstruct.2015.12.045.
[35] A. M. Araba and A. F. Ashour, Flexural performance of hybrid GFRP-Steel reinforced concrete continuous beams, Compos. Part B Eng.,  154 (2018) 321–336. https://doi.10.1016/j.compositesb.2018.08.077.
[36] S. A. A. Mustafa and H. A. Hassan, Behavior of concrete beams reinforced with hybrid steel and FRP composites, HBRC J.,  14 (2018) 300–308. https://doi.10.1016/j.hbrcj.2017.01.001.
[37] T. Renić, I. Hafner, and T. Kišiček, ‘Ductility of hybrid FRP – steel reinforced concrete sections’, Proceedings of the 2nd International Conference CoMS 2020/21, no. May, 118–126, 2021.
[38] P. D. Nguyen, V. H. Dang, and N. A. Vu, Performance of concrete beams reinforced with various ratios of hybrid GFRP/steel bars, Civ. Eng. J., 6 (2020) 1652–1669. https://doi.10.28991/cej-2020-03091572.
[39] S. Moolaei, M. K. Sharbatdar, and A. Kheyroddin, Experimental evaluation of flexural behavior of HPFRCC beams reinforced with hybrid steel and GFRP bars, Compos. Struct.,  (2021)  275. https://doi.10.1016/j.compstruct.2021.114503.
[40] H. D. Vu and D. N. Phan, Experimental and Theoretical Analysis of Cracking Moment of Concrete Beams Reinforced with Hybrid Fiber Reinforced Polymer and Steel Rebars, Adv. Technol. Innov., 6 (2021) 222–234. https://doi.10.46604/aiti.2021.7330.
[41] W. Abdullah, Z. Z. Zhuang, and R. X. Jie, Flexural Behavior of Concrete Beams Reinforced With Hybrid FRP Bars and HRB Bars, IOSR J. Eng.,  9 (2019) 25–33. https://doi.10.1061/(asce)cc.1943-5614.0000035.
[42] H. Y. Leung, and R. V. Balendran, Flexural behaviour of concrete beams internally reinforced with GFRP rods and steel rebars, Struct. Surv.,21 (2003)  146–157. https://doi.org/10.1108/02630800310507159
[43] D. Lau and H. Pam, Experimental study of reinforced concrete beams, Eng. Struct., 32 (2010) 3857–3865.
[44] G. Xingyu, D. Yiqing, and J. Jiwang, Flexural behavior investigation of steel-GFRP hybrid-reinforced concrete beams based on experimental and numerical methods, Eng. Struct., (2020) 206. https://doi.10.1016/j.engstruct.2019.110117.
[45] K. Sijavandi, M. K. Sharbatdar, and A. Kheyroddin, Experimental evaluation of flexural behavior of High-Performance Fiber Reinforced Concrete Beams using GFRP and High Strength Steel Bars, Structures, 33 (2021)  4256–4268. https://doi.10.1016/j.istruc.2021.07.020.
[46] M. Said, A. S. Shanour, T. S. Mustafa, A. H. Abdel-kareem, and M. Khalil, Experimental flexural performance of concrete beams reinforced with an innovative hybrid bars, Eng. Struct., 226, 2021.
[47] Y. S. Yoon, J. M. Yang, K. H. Min, and H. O. Shin, Flexural strength and deflection characteristics of high-strength concrete beams with hybrid FRP and steel bar reinforcement, in Special Publication, 2011, 1–22.
[48] Z. Y. Sun, Y. Yang, W. H. Qin, S. T. Ren, and G. Wu, Experimental study on flexural behavior of concrete beams reinforced by steel-fiber reinforced polymer composite bars, J. Reinf. Plast. Compos., 31 (2021) 1737–1745. https://doi.10.1177/0731684412456446.
[49] M. A. L. O. Aiello, Structural performances of concrete beams with hybrid (fiber-reinforced polymer-steel) reinforcements, J. Compos. Constr., 6 (2002) 133–140. https://doi.10.1061/(asce)1090-0268(2002)6:2(133)
[50] M. A. Safan, Flexural behavior and design of steel-GFRP reinforced concrete beams, ACI Mater. J., 110 (2013) 667.
[51] D. P. Nguyen and V. Q. Dang, Limiting Reinforcement Ratios for Hybrid GFRP/Steel Reinforced Concrete Beams, Int. J. Eng. Technol. Innov., 11 (2021) 01–11. https://doi.10.46604/IJETI.2021.6660.
[52] D. Y. Yoo, N. Banthia, and Y. S. Yoon, Flexural behavior of ultra-high-performance fiber-reinforced concrete beams reinforced with GFRP and steel rebars, Eng. Struct., 111 (2016) 246–262.  https://doi.10.1016/j.engstruct.2015.12.003.
[53] S. Kartal, I. Kalkan, A. Beycioglu, and M. Dobiszewska, Load-deflection behavior of over-and under-reinforced concrete beams with hybrid frp-steel reinforcements, Materials, 14 (2021) . https://doi.10.3390/ma14185341.
[54] K. H. Tan, Behaviour of hybrid FRP-steel reinforced concrete beams, in In Proc., 3rd Int. Symposium, FRPRCS, 487–494,1997.
[55] W. Ge, J. Zhang, D. Cao, and Y. Tu, Flexural behaviors of hybrid concrete beams reinforced with BFRP bars and steel bars, Constr. Build. Mater., 87 (2015) 28–37. https://doi.10.1016/j.conbuildmat.2015.03.113.
[56] G. B. Maranan, A. C. Manalo, B. Benmokrane, W. Karunasena, P. Mendis, and T. Q. Nguyen, Flexural behavior of geopolymer-concrete beams longitudinally reinforced with GFRP and steel hybrid reinforcements, Eng. Struct., 182 (2019)  141–152. https://doi.10.1016/j.engstruct.2018.12.073.
[57] R. Thamrin, Z. Zaidir, and D. Iwanda, Ductility Estimation for Flexural Concrete Beams Longitudinally Reinforced with Hybrid FRP–Steel Bars, Polymers, (2022) 14 . https://doi.10.3390/polym14051017.
[58] P. Gergely and L. A. Lutz, Maximum crack width in reinforced concrete flexural members, Spec. Publ., 20 (1968) 87–117.
[59] H. Huang, Experimental study of steel-GFRP reinforced concrete beam, Shanghai: Tongji University, 2004.
[60] L. Yinghao and Y. Yong, Arrangement of hybrid rebars on flexural behavior of HSC beams, Compos. Part B Eng., 45 (2013) 22–31. https://doi.10.1016/j.compositesb.2012.08.023.
[61] X. Ruan, C. Lu, K. Xu, G. Xuan, and M. Ni, Flexural behavior and serviceability of concrete beams hybrid-reinforced with GFRP bars and steel bars, Compos. Struct., 235 (2020) 111772. https://doi.10.1016/j.compstruct.2019.111772.