Mohammed Ashrafuddin2022-05-182022-05-184969https://drepo.sdl.edu.sa/handle/20.500.14154/1658The work in this thesis focuses on an experimental investigation to characterize ultimate load levels and failure mode characteristics of reinforced concrete (R/C) beams strengthened or repaired by bonding external plates to soffit of the R/C beam. The experimental investigation is designed so as to induce not only flexural failure and concrete rip-off failure in the repaired beams but also a diagonal tension failure similar to unplated R/C beams. Parametric constraints leading to diagonal tension failure in plated beams in contrast to flexural failure and rip-off failure are defined. A total of twenty eight R/C beams repaired by plate bonding were tested and data was generated to yield ultimate load levels, mode of failure and central beam deflection. Existing model for predicting rip-off failure was confirmed in terms of ultimate load levels and mode of failure, and a new predictor equation is proposed for determination of ultimate load for plated beams prone to fail under diagonal tension.enThesis