الفهرس 
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Abstract
The existence of transverse openings in floor beams are more often used to
provide passage for utility duct and pipes, it also translates into substantial
economic savings in the construction of a multi-storey building. However
providing an opening in the beam causes cracks around the opening thus reduce
the beam stiffness, which leads to the need of strengthening such beams
Recently, strengthening of reinforced concrete (RC) beams subjected to
torsion is receiving increased attention. Torsion is considered one of the main
factors affecting the stability of structural elements. Structural elements
subjected to torsion experience diagonal tension and compression and fails in a
brittle manner which may result in a progressive collapse of the building. In this
thesis the use of externally bonded fiber reinforced polymers (EB-FRP) to
strengthen and retrofitting beams with web opening subjected to pure torsion are
discussed.
In this thesis, an experimental work has been carried out to investigate the
torsional behavior up to failure of nine reinforced concrete beams having the
same dimensions and reinforcement. One of them is solid without opening as a
reference beam and one of the remaining eight beams was tested without any
retrofitting and the others were retrofitted with variable schemes of EB-FRP.
Also a finite element analysis (FEA) numerical models using ANSYS computer
program (Version 14.0) has been used to analyze the three dimensional model
for the proposed experimental models -. The FEA covers the torsional moment
versus twisting angle behavior, strain in concrete, strain in reinforcement, steel
rebar and EB-FRP, and failure modes. The nonlinear material and geometrical
analysis based on Incremental Iterative load method is adopted.