Behavior of RC Beams Retrofitted/Strengthened With External Post-Tension System

This paper presents a study on the flexural behavior of strengthened RC beams using external post-tensioning technique under the effect of cyclic loads. Post tensioning techniques is a new method to improve the behavior of cracked and sound beams. This new technique was used in this research to improve the behavior of cracked and un-cracked beams. The study consists of two stages, the first stage is an experimental program which is carried out in lap to test casted beams, and the second stage is a theoretical program which was carried out to verify the results of experimental program. The behavior of RC beams in different levels of cracks was studied, crack pattern was observed and failure type was recorded. Comparisons between the behaviors of different RC beams were performed. The experimental study included using of prestressing steel bars, GFRP bars and the effect of different percentage of shear reinforcement was also taken into consideration. Specimens were tested under the effect of cyclic load. Finally the simulations of tested beams were modeled in finite element software (ANSYS) to verify the results of experimental work compared to theoretical analysis