![]() | Only 14 pages are availabe for public view |
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. |