الفهرس 
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Abstract
Researchers have not widely considered the behavior of inverted-T (IT) beams experiencing ledge failures. In this study, an experimental program has been carried out in order to examine the behavior of ledge beam systems. The program included the testing of eight specimens, where the influence of ratio of ledge tie reinforcement and the effect of concrete strength on the behavior of NSC and HSC ledge beams have been considered. In addition, a numerical study based on the nonlinear finite element analysis has been conducted via the computer program ABAQUS. Besides, the method of strut-and-tie method has been employed for strength assessment of the test specimens. Also, the design provisions from the American Association of State Highway Officials (AASHTO LRFD 2012) and American Concrete Institute Code (ACI 318-14) when applied to both NSC and HSC ledge beams have been evaluated. The results from the behavior and failure of the tested specimens clarified that the method of strut-and-tie model can be used in developing a reliable and safe design. On the other hand, the nonlinear finite element analysis can serve in the optimization of the design capacity and in the simulation of the tests, different failure mechanisms of ledges (ledge flexure and ledge shear friction being most critical). The results revealed that with the increase of concrete strength increases the strength of the ledge and reduces the deformations. Also, it is appeared that increasing the ratio of ledge tie reinforcement led to increasing the strength and makes such element more ductile.