Imparting Ductility to FRP-Reinforced Concrete Beams Through Compression Zone Confinement

Shi-Shun Zhang; Xiao-Bing Hu; Jin-Guang Teng

doi:10.1016/j.eng.2026.04.012

Engineering ›› :202604012 DOI: 10.1016/j.eng.2026.04.012

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Imparting Ductility to FRP-Reinforced Concrete Beams Through Compression Zone Confinement

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Abstract

In recent decades, fiber-reinforced polymer (FRP) bar-reinforced concrete (FRP-RC) beams have attracted considerable attention as a corrosion-free beam form. However, FRP-RC beams have limited practical applications owing to their much lower ductility compared to conventional steel bar-reinforced concrete (steel-RC) beams. To improve the ductility of FRP-RC beams, this study presents an innovative sectional form for FRP-RC beams in which the compression zone concrete is confined with FRP spirals/hoops. With such a sectional form, the ductility of the beam is derived from the ductile behavior of confined concrete in the compression zone instead of the ductile behavior of steel yielding in a conventional steel-RC beam. An experimental program consisting of eight large-scale FRP-RC beams was conducted to validate the effectiveness of this sectional form, in which the variables investigated include the pitch of the FRP spiral used to offer confinement, amount of longitudinal tension FRP bars, and FRP confinement configuration. The test results demonstrate the effectiveness of FRP confinement in improving the ductility and load-carrying capacity of FRP-RC beams; for one of the beams tested in the present study, ductility was increased by 150% with only a corresponding cost increase of around 7%. The significant effects of design parameters on the behavior of such FRP-RC beams are clearly revealed. Finally, a finite element model for such FRP-RC beams was established and verified using the test results.

Keywords

FRP bar-reinforced concrete (FRP-RC) beam / Ductility / FRP confinement / Compression zone / Load-carrying capacity

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Shi-Shun Zhang, Xiao-Bing Hu, Jin-Guang Teng. Imparting Ductility to FRP-Reinforced Concrete Beams Through Compression Zone Confinement. Engineering 202604012 DOI:10.1016/j.eng.2026.04.012

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References

Publishing order | Descend order by publishing year | Descend order by cited within

[1]	Pilakoutas K , Neocleous K , Guadagnini M . Design philosophy issues of fiber reinforced polymer reinforced concrete structures. J Compos Constr 2002; 6(3):154—61.

[2]	Karbhari VM , Chin JW , Hunston D , Benmokrane B , Juska T , Morgan R , et al. Durability gap analysis for fiber—reinforced polymer composites in civil infrastructure. J Compos Constr 2003; 7(3):238-47.

[3]	Hollaway LC , Teng JG . Strengthening and rehabilitation of civil infrastructures using fibre—reinforced polymer (FRP) composites. Cambridge: Woodhead Publishing; 2008.

[4]	Liu KC , Jiang C , Yu T , Teng JG . Compressive behaviour of elliptical FRP tube—confined concrete columns. Compos Struct 2023; 303:116301.

[5]	Ueda T. Material mechanical properties necessary for the structural intervention of concrete structures. Engineering 2019; 5(6):1131-8.

[6]	Smits J. Fiber—reinforced polymer bridge design in the Netherlands: architectural challenges toward innovative, sustainable, and durable bridges. Engineering 2016; 2(4):518-27.

[7]	Ceroni F , Cosenza E , Gaetano M , Pecce M . Durability issues of FRP rebars in reinforced concrete members. Cem Concr Compos 2006; 28(10):857-68.

[8]	Kassem C , Farghaly AS , Benmokrane B . Evaluation of flexural behavior and serviceability performance of concrete beams reinforced with FRP Bars. J Compos Constr 2011; 15(5):682—95.

[9]	Elgabbas F , Vincent P , Ahmed EA , Benmokrane B . Experimental testing of basalt—fiber—reinforced polymer bars in concrete beams. Compos Pt B Eng 2016; 91:205-18.

[10]	Barris C , Torres L , Turon A , Baena M , Catalan A . An experimental study of the flexural behaviour of GFRP RC beams and comparison with prediction models. Compos Struct 2009; 91(3):286—95.

[11]	Zou PXW . Flexural behavior and deformability of fiber reinforced polymer prestressed concrete beams. J Compos Constr 2003; 7(4):275—84.

[12]	Zhou YW, Wu YF, Teng JG, Leung AYT. Ductility analysis of compression—yielding FRP—reinforced composite beams. Cem Concr Compos 2009; 31(9):682—91.

[13]	Nanni A. Flexural behavior and design of RC members using FRP reinforcement. J Struct Eng 1993; 119(11):3344-59.

[14]	El—Nemr A , Ahmed EA , Benmokrane B . Flexural behavior and serviceability of normal— and high—strength concrete beams reinforced with glass fiber—reinforced polymer bars. ACI Struct J 2013; 110(06):1077-87.

[15]	Maranan GB , Manalo AC , Benmokrane B , Karunasena W , Mendis P . Evaluation of the flexural strength and serviceability of geopolymer concrete beams reinforced with glass—fibre—reinforced polymer (GFRP) bars. Eng Struct 2015; 101:529—41.

[16]	Lau D , Pam HJ . Experimental study of hybrid FRP reinforced concrete beams. Eng Struct 2010; 32(12):3857-65.

[17]	Wu YF . Ductility demand of compression yielding fiber—reinforced polymer—reinforced concrete beams. ACI Struct J 2008; 105(1):104—10.

[18]	Wu YF . New avenue of achieving ductility for reinforced concrete members. J Struct Eng 2006; 132(9):1502-6.

[19]	Wu YF , Jiang JF , Liu K . Perforated SIFCON blocks—an extraordinarily ductile material ideal for use in compression yielding structural systems. Constr Build Mater 2010; 24(12):2454-65.

[20]	Teng JG , Zhang B , Zhang SS , Fu B . Steel—free hybrid reinforcing bars for concrete structures. Adv Struct Eng 2018; 21(16):2617-22.

[21]	Zhang SS , Liu YX , Ke Y , Nie XF , Yu T . Novel FRP—RC beams with ductile FRP—UHPC hybrid rebars in the compression zone: flexural behaviour. Constr Build Mater 2025; 460:139758.

[22]	Wang HZ , Belarbi A . Ductility characteristics of fiber—reinforced—concrete beams reinforced with FRP rebars. Constr Build Mater 2011; 25(5):2391-401.

[23]	Yuan F , Pan JL , Leung CKY . Flexural behaviors of ECC and concrete/ECC composite beams reinforced with basalt fiber—reinforced polymer. J Compos Constr 2013; 17(5):591-602.

[24]	Wang HW , Xu JJ , Jiang X , Han XY , Pan KM , Yu RC , et al. Flexural behavior of GFRP—RC beams confined with CFRP in compression zone. Eng Struct 2024; 302:117348.

[25]	Deng X , Tang S , Tang J , Liu S , Yang S . Experimental study of the flexural performance of GFRP—reinforced seawater sea sand concrete beams with built—in GFRP tubes. Materials 2024; 17(13):3221.

[26]	Tahrirchi EJ, Alaee F, Jalali M. Experimental investigation of ductility in GFRP RC beams by confining the compression zone. Adv Civ Eng 2024; 2024:1-21.

[27]	Burgoyne CJ . Rational use of advanced composites in concrete. Proc Inst Civ Eng Struct Build 2001; 146(3):253-62.

[28]

Burgoyne CJ , Leung HY . Test on prestressed concrete beam with AFRP spiral confinement and external aramid tendons. In: Proceedings of the Antoine E. Naaman Symposium—Four Decades of Progress in Prestressed Concrete, FRC, and Thin Laminate Composite; 2010 Nov 11—14; Ann Arbor, MI, USA. Farmington Hills: American Concrete Institute (ACI); 2010. p. SP—272.

[29]	Pantelides CP , Gibbons ME , Reaveley LD . Axial load behavior of concrete columns confined with GFRP spirals. J Compos Constr 2013; 17(3):305-13.

[30]	Afifi MZ , Mohamed HM , Benmokrane B . Axial capacity of circular concrete columns reinforced with GFRP bars and spirals. J Compos Constr 2014; 18(1):04013017.

[31]	Hu XB , Nie XF , Wang JJ , Zhang SS . Behavior of FRP spiral—confined concrete under concentric compression. Eng Struct 2024; 321:118898.

[32]	Hu XB , Nie XF , Wang JJ , Yu T , Zhang SS . Experimental study on GFRP spiral—confined concrete under eccentric compression. Compos Struct 2025; 354:118793.

[33]	Ministry of Housing and Urban—Rural Development of the People’s Republic of China . GB 50608—2020: Technical standard for fiber reinforced polymer (FRP) in construction. Chinese standard. Beijing: China Architecture and Building Press; 2020. [Chinese].

[34]	American Society for Testing and Materials (ASTM). ASTM C39/C39M—18: Standard test method for compressive strength of cylindrical concrete specimens. ASTM standard. West Conshohocken: ASTM; 2018.

[35]	American Society for Testing and Materials (ASTM). ASTM D7205/D7205M—11: Standard test method for tensile properties of fiber reinforced polymer matrix composite bars. West Conshohocken: ASTM; 2011.

[36]	International Organization for Standardization (ISO).ISO 104061—1:2015: Fibre—reinforced polymer (FRP) reinforcement of concrete: test methods: part 1: FRP bars and grids. Geneva: ISO; 2015.

[37]	Huang ZJ , Chen WS , Tran TT , Pham TM , Hao H , Chen ZY , et al. Experimental and numerical study on concrete beams reinforced with basalt FRP bars under static and impact loads. Compos Struct 2021; 263:113648.

[38]	Al—Sunna R , Pilakoutas K , Hajirasouliha I , Guadagnini M . Deflection behaviour of FRP reinforced concrete beams and slabs: an experimental investigation. Compos Pt B Eng 2012; 43(5):2125-34.

[39]	Adam MA , Said M , Mahmoud AA , Shanour AS . Analytical and experimental flexural behavior of concrete beams reinforced with glass fiber reinforced polymers bars. Constr Build Mater 2015; 84:354-66.

[40]	Elgabbas F , Ahmed EA , Benmokrane B . Flexural behavior of concrete beams reinforced with ribbed basalt—FRP bars under static loads. J Compos Constr 2017; 21(3):04016098.

[41]	Ashour SA. Effect of compressive strength and tensile reinforcement ratio on flexural behavior of high—strength concrete beams. Eng Struct 2000; 22(5):413-23.

[42]	Mahin SA , Bertero VV . Problems in establishing and predicting ductility in structural design. In: Proceedings of the International Symposium on Earthquake Structural Engineering; 1976 Aug 19—21; St. Louis, MO, USA. Washington, DC: National Science Foundation; 1976. p. 613-28.

[43]	Park R. Evaluation of ductility of structures and structural assemblages from laboratory testing. Bull N Z Soc Earthq Eng 1989; 22(3):155—66.

[44]	Naaman AE , Jeong SM . Structural ductility of concrete beams prestressed with FRP tendons. In: Proceedings of the 2nd International RILEM Symposium on Non—metallic (FRP) Reinforcement for Concrete Structures; 1995 Aug 23—25; Ghent, Belgium. Boca Raton: CRC Press; 1995. p. 379-86.

[45]	ABAQUS. ABAQUS analysis user’s manual (version 6.14). Mayfield Heights: Dassault Systèmes SIMULIA Corporation; 2014.

[46]	Zeng JJ , Ye YY , Liu WT , Zhuge Y , Liu Y , Yue QR . Behaviour of FRP spiral—confined concrete and contribution of FRP longitudinal bars in FRP—RC columns under axial compression. Eng Struct 2023; 281:115747.

[47]	Ministry of Housing and Urban—Rural Development of the People’s Republic of China . GB 50010—2010: Code for design of concrete structures. Chinese standard. Beijing: China Architecture & Building Press; 2010. Chinese.

[48]	American Concrete Institute (ACI) . ACI—318: Building code requirements for structural concrete and commentary. ACI standard. Farmington Hills: ACI; 2019.

[49]	Zinkaah OH , Alridha Z , Alhawat M . Numerical and theoretical analysis of FRP reinforced geopolymer concrete beams. Case Stud Constr Mater 2022; 16:e01052.

[50]	Nie XF , Zhang SS , Chen GM , Yu T . Strengthening of RC beams with rectangular web openings using externally bonded FRP: numerical simulation. Compos Struct 2020; 248:112552.

[51]	Ke Y , Zhang SS , Nie XF , Yu T , Yang YM , Jedrzejko MJ . Finite element modelling of RC beams strengthened in flexure with NSM FRP and anchored with FRP U—jackets. Compos Struct 2022; 282:115104.

[52]	Zhang SS , Zhang DD , Nie XF . Behavior of RC interior beam—to—column joints with FRP—strengthened beam web openings under cyclic loading. Eng Struct 2025; 324:119373.