Retrofitting of RCC Beams in the Shear Region Using Carbon Fiber-Reinforced Polymer
DOI:
https://doi.org/10.59675/E312Keywords:
RCC, Retrofitting, Shear Region, Carbon Fiber, BeamAbstract
In recent years, Fiber Reinforced Polymers (FRPs) have gained significant popularity over traditional materials for enhancing the shear strength of Reinforced Concrete (RC) beams, particularly when they are deficient in shear or prone to shear failure. FRPs are advanced composite materials widely used to retrofit existing RC beams and improve the shear resistance of new ones. Among these, Carbon Fiber Reinforced Polymers (CFRP) stand out due to their lightweight nature, exceptional tensile strength, superior corrosion resistance, and ease of application in construction. Shear failure is commonly observed under seismic and impact loading conditions, making CFRP reinforcement a complex but essential solution. Although extensive research has been conducted in this field, existing studies remain insufficient. This study focuses on strengthening RC beams in shear using CFRP. A total of six simply supported RC beams (150 mm × 200 mm × 1800 mm) were subjected to four-point bending tests. The primary objective is to enhance the shear load-bearing capacity of the beams. The research involved testing RC beams reinforced with CFRP, including two control specimens and four beams wrapped with a single layer of CFRP. The wrapping configurations included two beams with 356 mm CFRP wrapping and two with 508 mm wrapping. The average maximum load capacity of the unwrapped beams was recorded at 84.74 kN, while those wrapped with 356 mm CFRP reached 120.46 kN. Meanwhile, the beams wrapped with 508 mm CFRP demonstrated an increased load capacity of 155.815 kN. Cracking was observed earlier in the unwrapped beams compared to those strengthened with CFRP, indicating improved structural performance. The failure patterns of the beams varied, particularly between those with and without CFRP wrapping. This study highlights CFRP's potential and provides a foundation for future research on optimizing its configurations for infrastructure rehabilitation.
References
Awad ZK, Aravinthan T, Zhuge Y, Gonzalez F. A review of optimization techniques used in the design of fibre composite structures for civil engineering applications. Mater Des. 2012;33:534-44. DOI: https://doi.org/10.1016/j.matdes.2011.04.061
Abdel-Kareem AH. Shear strengthening of reinforced concrete beams with rectangular web openings by FRP Composites. Adv Concr Constr. 2014;2(4):281. DOI: https://doi.org/10.12989/acc.2014.2.4.281
Cantwell WJ, Morton J. The impact resistance of composite materials—a review. Composites. 1991;22(5):347-62. DOI: https://doi.org/10.1016/0010-4361(91)90549-V
Nanni A, Saadatmanesh H, Ehsani MR, Ahmad S, Dolan CW, Marsh H, et al. State of the Art Report on Fiber Reinforced Plastic (FRP) Reinforcement for Concrete Structures. ACI Struct J. 1996;440R-1.
Moradi E, Naderpour H, Kheyroddin A. An experimental approach for shear strengthening of RC beams using a proposed technique by embedded through-section FRP sheets. Compos Struct. 2020;238:111988. DOI: https://doi.org/10.1016/j.compstruct.2020.111988
Godat A, Hammad F, Chaallal O. State-of-the-art review of anchored FRP shear-strengthened RC beams: A study of influencing factors. Compos Struct. 2020;254:112767. DOI: https://doi.org/10.1016/j.compstruct.2020.112767
Fang H, Bai Y, Liu W, Qi Y, Wang J. Connections and structural applications of fibre reinforced polymer composites for civil infrastructure in aggressive environments. Compos Part B Eng. 2019;164:129-43. DOI: https://doi.org/10.1016/j.compositesb.2018.11.047
Islam GS, Chowdhury FH, Dev A. Pre-cracked RC beam strengthening with CFRP materials.
Islam SMZ, Ahmed B, Islam MS, Ferdous MR, Ali MW. FRP-adhesive materials for strengthening of RC beams at flexure and shear region. J Eng Appl Sci. 2019;3:33-44.
Byrne D, Tikka T. Repair and strengthening of severely damaged concrete beams with externally bonded CFRP. Adv Compos Mater Bridges Struct. 2008;80-5.
Zhang Z, Hsu CTT, Moren J. Shear strengthening of reinforced concrete deep beams using carbon fiber reinforced polymer laminates. J Compos Constr. 2004;8(5):403-14. DOI: https://doi.org/10.1061/(ASCE)1090-0268(2004)8:5(403)
Bousselham A, Chaallal O. Experimental investigations on the influence of size on the performance of RC T-beams retrofitted in shear with CFRP fabrics. Eng Struct. 2013;56:1070-9. DOI: https://doi.org/10.1016/j.engstruct.2013.06.028
Donchev T, Thomopoulos G, Bradsell C. Application of FRP materials for retrofitting of RC beams after shear failure. In: 4th Int Conf FRP Compos Civ Eng (CICE); 2008 Jul; p. 1-6.
Colalillo MA, Sheikh SA. Seismic retrofit of shear-critical RC Beams using CFRP. Report no. FRPRCS-9, Sydney, Australia. 2009.
Lombard JC. Seismic strengthening and repair of reinforced concrete shear walls using externally bonded carbon fibre tow sheets [Doctoral dissertation]. Carleton University; 1999.
Ahmed EA, El-Salakawy E, Benmokrane B. Shear strengthening of RC beams reinforced with FRP stirrups. Adv Compos Mater Bridges Struct. 2008;25-30.
Bousalem B, Chikh N, Benzaid R. Flexural Strengthening of Reinforced Concrete Beams with NSM Fiber-Reinforced Polymer Strips. Available from: http://www.enset-oran.dz/sbeidco/Papers/36_Paper.pdf
Li A, Assih J, Delmas Y. Shear strengthening of RC beams with externally bonded CFRP sheets. J Struct Eng. 2001;127(4):374-80. DOI: https://doi.org/10.1061/(ASCE)0733-9445(2001)127:4(374)
Ibrahim B, Leblouba M, Al-Toubat S, Barakat S. Shear strength of FRP-externally strengthened high strength RC T-beams. In: IOP Conf Ser: Mater Sci Eng. 2019 Aug;601(1):012018. DOI: https://doi.org/10.1088/1757-899X/601/1/012018
Mofidi A, Chaallal O. Shear strengthening of RC beams with externally bonded FRP composites: Effect of strip-width-to-strip-spacing ratio. J Compos Constr. 2011;15(5):732-42. DOI: https://doi.org/10.1061/(ASCE)CC.1943-5614.0000219
Ahmad SS, El-kholy AI. Effect of Drilling Geometry on the Behavior of Rc Beams Strengthened With Cfrp Laminates. East Afr Sch J Eng Comput Sci. 2019;2(7):182-90.
Shakor P, Hasan S, Awuzie BO, Singh AK, Rauniyar A, Karakouzian M. Evaluating the potential of geopolymer concrete as a sustainable alternative for thin white-topping pavement. Front Mater. 2023;10:1181474. DOI: https://doi.org/10.3389/fmats.2023.1181474
Shit T. Experimental and numerical study on behavior of externally bonded RC T-beams using GFRP composites [Doctoral dissertation]. 2011.
Ekenel M, Stephen V, Myers JJ, Zoughi R. Microwave NDE of RC beams strengthened with CFRP laminates containing surface defects and tested under cyclic loading. Electr Comput Eng, Univ Missouri-Rolla, Rolla, MO. 2004;1-8.

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