Behavior of R.C. Beams with Openings using Different Strengthening Techniques
Keywords:
Opening, Shear, Flexural, Strengthening, FRP, NSM, ductility.Abstract
An extensive experimental program was performed to investigate the performance of R.C. beams with opening either strengthened or un- strengthened. A total of 24 specimens were tested on two series to examine the effect of openings on the behavior of RC beams according to the opening shape, aspect ratio and orientation having same area of the opening in shear and flexural zones, also study the effect of the different strengthening methods for the openings on the behavior of RC beams either using internal strengthening such as internal steel reinforcement (I.S.R.), internally embedded fiber reinforced bars, and near surface mounted using FRP laminate (N.S.M.) or using external bonding strengthening (E.B.) such as externally bonded FRP laminates and steel box. All specimens tested under three points loading, the effective span of beams was 1500 mm, also all specimens designed to govern failure in flexure before shear. Based on the experimental evidence, in the 1st series circular openings showed the least reduction in the beam’s load capacity when compared to rectangular and square openings regarding all the openings shapes have the same area. The 2nd series showed the effect of strengthening the openings on the behavior of beams, the use of CFRP externally bonded improves both beam’s strength and ductility but to different extents than any different method of strengthening.
References
. Tamer El-Maaddawy and Bilal El-Arises, “Behavior of Concrete Beams with Short Shear Span and Web Opening Strengthened in Shear with CFRP Composites” Journal of Composites for construction, ACE, pp47/59, January/ February 2012
. Mansur, M. “Effect of openings on the behavior and strength of R/C beams in shear.” Cem. Concr. Compos., 20(6), 477–486, 1998
. Mansur, M., Tan, K., and Wei,W. “Effects of creating an opening in existing beam.” ACI Struct. J., 96(6), 899–906,1999.
. Ashour, A., and Rishi, G. “Tests of reinforced concrete continuous deep beams with web openings.” ACI Struct. J., 97(3), 418–426, 2000.
. Tan, K., Mansur, M., and Wei, W. “Design of reinforced concrete beams with circular openings.” ACI Struct. J., 98(3), 407–415, 2001.
. Bengi Aykac, Ilker Kalkan, Sabahattin Aykac, Yusuf Emre Egriboz “ Flexural behavior of RC beams with regular square or circular web Openings” Engineering Structure, 56, pp2165- 2174, 2013
. Mansur M A, Lee Y F, Tan K H, Lee S L “Tests on RC continuous beams with openings”. J Struct Eng ASCE; 117:1593–606,1991
. Al-Sheikh S. A.” Flexural Behavior of R.C. Beams with opening. Concrete research letters, 5(2), 812-824.
. Tan KH, Mansur MA. Design procedure for reinforced concrete beams with large web openings. ACI Struct J;93:404–11,1996.
. Morsy, N. Elashkar, & K. Helmy. “A Comparative Study for Shear Strengthening Techniques of Reinforced Concrete Beams Using FRP”. Fourth international conference 4th International Conference on Concrete Repair, 2011 26th-28th September, Dresden, Germany
. Morsy, A., & Mahmoud, E. T.”Bonding techniques for flexural strengthening of R.C. beams using CFRP laminates”. Ain Shams Engineering Journal, 4(3), 369-374, 2011.
. Carolin, A., and Taljsten, B. (2005). “Experimental study of strengthening for increased shear bearing capacity.” J. Compos. Constr., 9(6), 488–496.
. Chaallal, O., Shahawy, M., and Hassan, M.. “Performance of reinforced concrete T-girders strengthened in shear with carbon fiber-reinforced polymer fabric.” ACI Struct. J., 99(3), 335–343, 2002
. Khalifa, A., and Nanni, A.. “Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP composites.” Constr. Build. Mater., 16(3), 135–146,2002.
. H A Abdalla, A M Torkey, H A Haggag, and A F Abu-Amira, “Design Against Cracking at Openings in Reinforced Concrete Beams Strengthened with Composite Sheets”.” Composite Structures, Vol 60, pp 7–204, 2003.
. Martinola, G., Meda, A., Plizzari, G. A., & Rinaldi, Z. “ Strengthening and repair of RC beams with fiber reinforced concrete”. Cement and Concrete Composites, 32(9), 731-739, 2010
. Pimanmas, A. . Strengthening R/C beams with opening by externally installed FRP rods: Behavior and analysis. Composite Structures, 92(8), 1957-1976, 2010.
. A., A., Naganathan, S., K., N., Fayyadh, M. M., & Jamali, S.”. Repair Effectiveness of Damaged RC Beams with Web Opening Using CFRP and Steel Plates”. Jordan Journal of Civil Engineering, 10(2), 163-183, 2010.
. Laura De Lorenzis, Antonio Nanni, “Shear Strengthening of Reinforced Concrete Beams with Near-Surface Mounted Fiber-Reinforced Polymer Rods”. Structural journal, 2001.
. Barros, J., & Dias, S.” Near surface mounted CFRP laminates for shear strengthening of concrete beams”. Cement and Concrete Composites, 28(3), 276-292, 2010
. Sunder, S., Babu, N., & Paulose, D. “ Experimental Study on Strengthening of Openings in R.C Beams using BFRP Fabric”. International Journal of Innovative Research in Science, Engineering and Technology, 5(8), 14849-14855, 2016.
. J.A Apeh , O.G Okoli , “Evaluation of Ductility Index of Concrete Beams Reinforced with Rebars Milled from Scrap metals”. Concrete Research Letters, 7(2), 56-68, 2016.
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