Behavior of R.C. Beams with Openings using Different Strengthening Techniques

Alaa M. Morsy, Amr M. Barima

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.


Keywords


Opening; Shear; Flexural; Strengthening; FRP; NSM; ductility.

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References


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