Main Article Content

Abstract

Due to the advantages of Fiber Reinforced Polymer (FRP) materials, they have been utilized to strengthen several reinforced concrete (RC) elements such as slabs, beams and columns. In this paper, five RC beams (200 mm width, 300 mm height, and 2750 mm length) were constructed. Four of these beams were strengthened with CFRP sheets whereas the last beam was used as a reference. Test parameters include the amount of FRP and the strengthening technique. Three strengthening techniques were used including the externally bonded technique (EB), the near surface mounted (NSM) technique using folded CFRP sheets inserted in near surface grooves, and a hybrid technique. All beams were tested under four point bending setup until failure. The control beam failed by the yielding of the tension steel followed by concrete crushing. The strengthened beams failed by steel yielding followed by either rupture or debonding of CFRP sheets at higher loads compared to the reference one. The stiffness after steel yielding and the ultimate capacity increased as the amount of CFRP increased. The strengthening technique affected the ultimate capacity of the strengthened beams. The NSM beam showed the lowest increase in the ultimate capacity (25.2%) whereas the hybrid beam showed the best performance with the highest increase in the ultimate capacity (58%) compared to the reference beam.

Keywords

Carbon fiber reinforced polymers Experimental work Flexural behavior Reinforced concrete beams Strengthening techniques.

Article Details

How to Cite
El Gamal, S., Al-Nuaimi, A., Al-Saidy, A., & Al-Shanfari, K. (2019). FLEXURAL BEHAVIOR OF RC BEAMS STRENGTHNED WITH CFRP SHEETS USING DIFFERENT STRENGTHENING TECHNIQUES. The Journal of Engineering Research [TJER], 16(1), 35–43. https://doi.org/10.24200/tjer.vol16iss1pp35-43

References

  1. Al Mahmoud F, Castel A, François R, Tourneur C (2009), Strengthening of RC members with near-surface mounted CFRP rods. Compos. Struct. 91(2): 138-147.
  2. Almusallam T.H, Al-Salloum Y.A, Alsayed SH, El-Gamal SE, Aqel M (2013), Tensile properties of glass fiber-reinforced polymer bars embedded in concrete under severe laboratory and field environmental conditions. Journal of Composite Materials, 47(4): 393-407.
  3. Al-Saidy A.H, Saadatmanesh H, El-Gamal S.E, Al-Jabri K.S, Waris B.M (2015), Structural behavior of corroded RC beams with/without stirrups repaired with CFRP sheets. Materials and Structures, 49(9): 3733-3747.
  4. Al-Salloum Y, El-Gamal SE, Almusallam T, Alsayed S, Aqel M (2013), Effect of harsh environmental conditions on the tensile properties of GFRP bars. Composites: Part B, 45(1): 835-844.
  5. Al-Tamimi1 A, Hawileh R, Abdalla J, Rasheed H (2011), Effects of Ratio of CFRP Plate Length to Shear Span and End Anchorage on Flexural Behavior of SCC RC Beams. J. Compos. Constr, 15(6): 908-919.
  6. Attari N.A, Amziane B.M, Chemrouk C (2012), An experimental study on the flexural response of partially bonded FRP strengthened concrete beams. Construction and Building Materials, 37: 746-757.
  7. BASF - Mbrace Saturant (2018) Available at: http://www.basf-cc.com.sg/en/products/ Concrete Repairand Protection Systems/ MBrace/ MBrace Saturant/Pages/default.aspx, (Accessed: 18 Feburary 2018).
  8. Ceroni F (2010), Experimental performances of RC beams strengthened with FRP materials. Construction and Building Materials, 24(9): 1547-1155.
  9. Choi H.T, West J.S, Soudki K.A (2011), Partially bonded near-surface mounted CFRP bars for strengthened concrete T-beams. Construction and Building Materials. 25(5): 2441-2449.
  10. Dong J, Wang Q, Guan Z (2013), Structural behavior of RC beams with external flexural and flexural–shear strengthening by FRP sheets. Composites Part B: Engineering, 44(1): 604-612.
  11. El-Gamal S.E, Al-Salloum Y, Alsayed S, Aqel M (2012), Performance of near surface mounted GFRP bars in concrete. Journal of Reinforced Plastics and Composites. 31(22): 1501-1515.
  12. El-Gamal S.E, Al-Nuaimi A, Al-Saidy A, Al-Lawati A (2014), Flexural strengthening of RC beams using near surface mounted fiber reinforced polymers. in Proc. of Brunei International Conference on Engineering and Technology. Institut Teknologi Brunei, Brunei Darussalam, 1-3 November 2014. DOI:10.1049/cp.2014.1082.
  13. El-Gamal SE, Al-Nuaimi A, Al-Saidy A, Al-Lawati A (2016), Efficiency of near surface mounted technique using fiber reinforced polymers for the flexural strengthening of RC beams. Construction and Building Materials. 118: 52-62.
  14. El-Gamal S.E, Al-Nuaimi A, Al-Saidy A, Al-Shanfari A (2017), Flexural behavior of reinforced concrete beams strengthened with carbon fiber reinforced polymer sheets using different bonding techniques. in Proc. of the 8th International Conference on Structural Engineering and Construction Management (ICSECM), Kandi, Srilanka.
  15. Hawileh R, Rasheed H, Abdalla J, Al-Tamimi A (2014), Behavior of reinforced concrete beams strengthened with externally bonded hybrid fiber reinforced polymer systems. Materials and Design. 53: 972-982.
  16. Jiangfeng D, Qingyuan W, Zhongwei G (2012), Structural behavior of RC beams with external flexural and flexural–shear strengthening by FRP sheets. Composites Part B. 44: 604-612.
  17. Jung W, Park J, Park Y (2007), A study on the flexural behavior of reinforced concrete beams strengthened with NSM prestressed CFRP reinforcements, in Proc. of the 8th International symposium on Fibre-reinforced polymer reinforcement for concrete structures (FRPRCS-8); Patras, Greece.
  18. Mostofinejad D and Shameli S (2011), Performance of EBROG method under multilayer FRP sheets for flexural strengthening of concrete beams. Procedia Engineering. 14: 3176-3182.
  19. Mostofinejad D and Shameli S.M (2013), Externally bonded reinforcement in grooves (EBRIG) technique to postpone debonding of FRP sheets in strengthened concrete beams. Construction and Building Materials. 38: 751-758.
  20. Rasheed H, Harrison R, Peterman R, Alkhrdaji T (2010), Ductile strengthening using externally bonded and near surface mounted, Composite Structure. 92: 2379-2393.
  21. Seracino R, Saifulnaz M.R, Oehlers D.J (2007), Generic debonding resistance of EB and NSM plate-to-concrete joints. J Compos Constr, 11(1): 62-70.
  22. Sharaky I.A, Torres L, Comas J, Barris C (2014), Flexural response of reinforced concrete (RC) beams strengthened with near surface mounted reinforced polymer (FRP) bars. Computational Structures 109: 8-22.
  23. SIKA Group, SikaWrap-230 (2018) Available at: http://gcc.sika.com/en/solutions_products/Construction/02a013/02a013sa06/02a013sa06100/02a013sa0613.html, (Accessed: 18 February 2018).
  24. Soliman S, El-Salakawy E, Benmokrane B (2011), Bond performance of near-surface-mounted FRP bars. Journal Composite Construcions 15(1): 103-111.