| Journal: |
International Journal of Trend in Research and Development, Volume 5(6), ISSN: 2394-9333
International Journal of Trend in Research and Development, Volume 5(6), ISSN: 2394-9333
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Volume: |
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| Abstract: |
A nonlinear Finite Element analysis of beams with
openings is conducted to study the influence of opening
location, from the face of support at the shear zone to mid-span
at the flexure zone, on the structural behavior of the beam. The
research also includes adopting two strengthening schemes
around the beam opening, and then assessing the structural
behavior of the strengthened beams, by studying the initial
crack load, failure load, deflections and failure mode. The
study consists of a control group of reinforced concrete beams;
one without an opening, and five with large openings each
beam with an opening at a different location measured from
the face of the support to the start of the opening at distances
of 0d , 0.5d ,1d , 2d, and 4.25d. The second strengthened group
of reinforced concrete beams includes ten beams, two for each
opening location, where for one beam the opening is
strengthened by full wrapping, whereas the other beam is
strengthened by inside wrapping only. The strengthening
material used is carbon fiber reinforced polymer CFRP fabric
adhered to the concrete surface using a suitable recommended
epoxy resin system. Numerical results of the nonlinear analysis
include, initial crack loads, ultimate failure loads, load
deflection curves, crack patterns, and failure modes for both
the reference and strengthened groups of beams. Large
openings in reinforced concrete beams have great structural
effect on their behavior, where initial cracking happens at
earlier loads, carrying capacities are reduced, stress
concentrations around opening corners, and higher deflections
are the predominant signs of premature failure. Comparative
studies are conducted and the influence of the opening location
is discussed where openings in the flexure zone (at the mid- span) are of less structural effect than opening closer to the
shear zone. Strengthening using CFRP fabric bounded
externally by a suitable epoxy resin system is successful where
wrapping around the opening proved to be superior to
wrapping inside the opening only scheme
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