Flexural response of FRP‑strengthened lightweight RC beams: hybrid bond efficiency of L-shape ribbed bars and NSM technique

• Autorzy: Tahmouresi Behzad , Momeninejad Kasra , Mohseni Ehsan
• Języki publikacji: EN

Abstrakty

EN

This paper presents the results of an experimental study on employing near surface mounted (NSM) fiber-reinforced polymer (FRP) reinforcement technique, and L-shape ribbed bars, for flexural strengthening of lightweight reinforced concrete (RC) beams. 18 RC beams including 14 lightweight RC beams and four normal-weight concrete beams were designed. The beams were strengthened with glass fiber-reinforced polymer (GFRP) bars and carbon fiber-reinforced polymer (CFRP) laminate in bending tests. Test parameters included: (1) different FRP materials (glass bars and carbon sheets), (2) longitudinal steel reinforcement ratio, and (3) type of strengthening technique used (NSM reinforcement or hybrid). The ultimate tensile strength, deflection, compressive and tensile strain of concrete, and failure mode of the beams were examined under four-point flexural test. Results showed that the ultimate strength of all RC beams increased between 33 and 105% compared to the control beam. The ultimate strength of beams reinforced with CFRP in the mid-span region was 10% higher than that of beams strengthened at both ends, although the former exhibited 28% lower ultimate deflection. The ultimate strength and deflection of RC beams strengthened with combined steel reinforcing bars and GFRP bars were 10% and 108% higher, respectively, compared to those of RC beams strengthened with GFRP bars only. Hybrid L-shape ribbed bars beams showed a considerably higher ductility (up to 170% increase in the ultimate deflection) compared to other beams. The comparison of the experimental results of the ultimate strength of the beams with ACI440-2R guidelines indicated a reasonable and conservative prediction of the code expression.

Słowa kluczowe

EN

glass fiber-reinforced polymer; GFRP; carbon fiber-reinforced polymer; CFRP; Lightweight RC beams; flexural strength; near-surface mounted; NSM; hybrid technique

PL

polimery wzmocnione włóknem szklanym; włókno szklane; włókno węglowe; belki lekkie; wytrzymałość na zginanie; montaż powierzchniowy; technika hybrydowa

• Wydawca: Springer ; Wrocław University of Science and Technology
• Czasopismo: Archives of Civil and Mechanical Engineering
• Rocznik: 2022
• Tom: Vol. 22, no. 2
• Strony: art. no. e95, 1--16
• Opis fizyczny: Bibliogr. 44 poz., il., tab., wykr., wzory

Twórcy

autor

Tahmouresi Behzad

• Department of Civil Engineering, University of Guilan, Rasht, Iran

autor

Momeninejad Kasra

• Department of Civil Engineering, University of Guilan, Rasht, Iran

autor

Mohseni Ehsan

• School of Architecture and Built Environment, University of Newcastle, Callaghan, Australia

• https://orcid.org/0000-0002-7755-2458

Bibliografia

• 1. Mostofinejad D, Akhlaghi A. Flexural strengthening of reinforced concrete beam-column joints using innovative anchorage system. ACI Struct J. 2017;114(6):1603-14.
• 2. Pour AF, Gholampour A, Ozbakkaloglu T. Influence of the measurement method on axial strains of FRP-confined concrete under compression. Compos Struct. 2018;188:415-424.
• 3. Liu W, Guo Z, Wang C, Niu S. Physico-mechanical and microstructure properties of cemented coal Gangue-Fly ash backfill: Effects of curing temperature. Constr Build Mater. 2021;299:124011.
• 4. Xiao X, Bu G, Ou Z, Li Z. Nonlinear in-plane instability of the confined FGP arches with nanocomposites reinforcement under radially-directed uniform pressure. Eng Struct. 2022;252:113670.
• 5. Sadrmomtazi A, Khabaznia M, Tahmouresi B. Effect of organic and inorganic matrix on the behavior of FRP-wrapped concrete cylinders. J Rehabil Civ Eng. 2016;2016:2.
• 6. Al-Salloum YA, et al. Effect of harsh environmental conditions on the tensile properties of GFRP bars. Compos B Eng. 2013;45(1):835-844.
• 7. El-Gamal S, et al. Performance of near surface mounted glass fiber reinforced polymer bars in concrete. J Reinf Plast Compos. 2012;31(22):1501-15.
• 8. Gholampour A, Ozbakkaloglu T. Extended constitutive model for FRP-confined concrete in circular sections. Adv Mater Res. 2017;2017:1142.
• 9. Lee D, Cheng L. Bond of NSM systems in concrete strengthening - examining design issues of strength, groove detailing and bond-dependent coefficient. Constr Build Mater. 2013;47:1512-22.
• 10. Bilotta A, et al. Bond efficiency of EBR and NSM FRP systems for strengthening concrete members. J Compos Constr. 2011;15(5):757-772.
• 11. De Lorenzis L, Rizzo A, La Tegola A. A modified pull-out test for bond of near-surface mounted FRP rods in concrete. Compos B Eng. 2002;33(8):589-603.
• 12. El-Saikaly G, Chaallal O. Fatigue behavior of RC T-beams strengthened in shear with EB CFRP L-shaped laminates. Compos B Eng. 2015;68:100-112.
• 13. De Lorenzis L, Teng J. Near-surface mounted FRP reinforcement: an emerging technique for strengthening structures. Compos B Eng. 2007;38(2):119-143.
• 14. Sharaky IA, et al. Effect of different material and construction details on the bond behaviour of NSM FRP bars in concrete. Constr Build Mater. 2013;38:890-902.
• 15. Ceroni F, et al. Bond behavior of FRP NSM systems in concrete elements. Compos B Eng. 2012;43(2):99-109.
• 16. Tanarslan H. The effects of NSM CFRP reinforcements for improving the shear capacity of RC beams. Constr Build Mater. 2011;25(5):2663-73.
• 17. Bianco V, Barros JA, Monti G. Three dimensional mechanical model for simulating the NSM FRP strips shear strength contribution to RC beams. Eng Struct. 2009;31(4):815-826.
• 18. Nanni A, Ludovico MD, Parretti R. Shear strengthening of a PC bridge girder with NSM CFRP rectangular bars. Adv Struct Eng. 2004;7(4):297-309.
• 19. Rizzo A, De Lorenzis L. Modeling of debonding failure for RC beams strengthened in shear with NSM FRP reinforcement. Constr Build Mater. 2009;23(4):1568-77.
• 20. Lorenzis LD, Nanni A. Characterization of FRP rods as near-surface mounted reinforcement. J Compos Constr. 2001;5(2):114-121.
• 21. Hassan T, Rizkalla S. Bond mechanism of NSM FRP bars for flexural strengthening of concrete structures. ACI Struct J. 2004;101(6):830-9.
• 22. El-Gamal S, et al. Efficiency of near surface mounted technique using fiber reinforced polymers for the flexural strengthening of RC beams. Constr Build Mater. 2016;118:52-62.
• 23. Sharaky IA, et al. Flexural response of reinforced concrete (RC) beams strengthened with near surface mounted (NSM) fibre reinforced polymer (FRP) bars. Compos Struct. 2014;109:8-22.
• 24. Farghal OA. Fatigue behavior of RC T-beams strengthened in shear with CFRP sheets. Ain Shams Eng J. 2014;5(3):667-680.
• 25. Mofidi A, et al. Performance of end-anchorage systems for RC beams strengthened in shear with epoxy-bonded FRP. J Compos Constr. 2011;16(3):322-331.
• 26. Guan Y, Jiang B, Song X. Experimental study and numerical simulation on bonding behavior of the new HB-FRP strengthening technology. J Perform Constr Facil. 2011;26(2):220-227.
• 27. Morsy A, Mahmoud ET. Bonding techniques for flexural strengthening of RC beams using CFRP laminates. Ain Shams Eng J. 2013;4(3):369-374.
• 28. Ozbakkaloglu T, Fang C, Gholampour A. Influence of FRP anchor configuration on the behavior of FRP plates externally bonded on concrete members. Eng Struct. 2017;133:133-150.
• 29. Mostofinejad D, Moghaddas A. Bond efficiency of EBR and EBROG methods in different flexural failure mechanisms of FRP strengthened RC beams. Constr Build Mater. 2014;54:605-614.
• 30. Kaya M, Kankal ZC. Effect of anchorage number on behavior of reinforced concrete beams strengthened with glass fiber plates. Int J Concrete Struct Mater. 2015;9(4):415-425.
• 31. Jumaat M, et al. Innovative end anchorage for preventing concrete cover separation of NSM Steel and CFRP bars strengthened RC beams. In: The 6th Jordanian international civil engineering conference, Amman, Jordan. 2015.
• 32. Mohseni E, Tang W, Wang S. Development of thermal energy storage lightweight structural cementitious composites by means of macro-encapsulated PCM. Constr Build Mater. 2019;225:182-195.
• 33. Tang W, Lo T, Balendran RV. Bond performance of polystyrene aggregate concrete (PAC) reinforced with glass-fibre-reinforced polymer (GFRP) bars. Build Environ. 2008;43(1):98-107.
• 34. Al-Ramahee MA, et al. Lightweight UHPC-FRP composite deck system. J Bridg Eng. 2017;22(7):04017022.
• 35. Al-Ramahee MA, et al. Lightweight UHPC-FRP composite Deck system. J Bridg Eng. 2017;22:7.
• 36. Aljaafreh T. Strengthening of lightweight reinforced concrete beams using carbon fiber reinforced polymers (CFRP). 2016.
• 37. Tang W, et al. Flexural strengthening of reinforced lightweight polystyrene aggregate concrete beams with near-surface mounted GFRP bars. Build Environ. 2006;41(10):1381-93.
• 38. Rahmanpour M, Afshin H. The combined retrofitting of reinforced light structural concrete beams in near joint by using of steel plates and CFRP jacket under cycling loads. 2016.
• 39. Shannag MJ, Al-Akhras NM, Mahdawi SF. Flexure strengthening of lightweight reinforced concrete beams using carbon fibre-reinforced polymers. Struct Infrastruct Eng. 2014;10(5):604-613.
• 40. ASTM A. C39/C39M-18. Standard test method for compressive strength of concrete, ASTM International. 2018.
• 41. Bakis CE, et al. Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures. Rep ACI Committee. 2002;440:1.
• 42. Sharaky I, et al. Effect of axial stiffness of NSM FRP reinforcement and concrete cover confinement on flexural behaviour of strengthened RC beams: experimental and numerical study. Eng Struct. 2018;173:987-1001.
• 43. Jeevan N, Reddy HJ. Strengthening of RC beams using externally bonded laminate (EBL) technique with end anchorages under flexure. Asian J Civ Eng. 2018;19(3):263-272.
• 44. Committee A. Building code requirements for structural concrete (ACI 318-05) and commentary (ACI 318R-05). 2005. American Concrete Institute.

Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023)