الفهرس | Only 14 pages are availabe for public view |
Abstract Many existing reinforced concrete(RC)buildings designed in accordance with obsolete codes are generally dominated by either shear failure in beam–column joints or weak column-strong beam behavior. This behavior can lead to premature failure under seismic loads.According to the demand of seismic concept design of buildings, frame structures should have multiple lines of seismic resistance, one of which is the strong column-weak beam. So the problem about strengthening of beam-column connections by increasing the capacity of those zones by externally bonded carbon-fiber reinforced polymer(CFRP),with the objective of relocating the potential plastic hinges from the columns to the beams needs to be investigated in depth. This research presents an experimental and numerical study of the cyclic structural performance of RC exterior beam–column joints. The present experimental program consists of testing eight 2/3 scale specimens; namely, a control specimen and seven strengthened specimens using four different strengthening schemes using CFRP sheets. Tests results indicate that CFRP sheets can change the failure pattern of RC frames from a typical ‘‘strong-column-weak-beam” failure to the ‘‘strong-beam-weak column” failure which is considered unacceptable strengthening technique. A nonlinear 2D, 3D and 1D-finite element models were established, a good agreement is observed between the FE results and experimental observations.The primary purpose of this investigation is to propose the best strengthening scheme to prevent columns or joints from failure, and shift the failure towards a beam flexural hinging mechanism that is a more ductile behavior. |