Strut and tie modeling of deep beams shear strengthened with FRP laminates

During the past two decades, the behaviour of slender beams shear strengthened with Fiber Reinforced Polymers (FRPs) laminates has been studied rigorously, and many design formulas have been proposed and adopted by the different codes of practice. On the other hand, deep beams which are usually designed using the Strut and Tie Modeling (STM) have had little attention. And although a number of studies have been conducted recently to address this issue, yet most of which only describe the behaviour of FRP strengthened deep beams without providing any design instructions. In this study and in order to address this issue, a Strut and Tie Modeling (STM) to assess the shear strength of FRP reinforced deep beams was proposed. The accuracy of the proposed STM was assessed and compared with other existing design provisions using a data base of 46 deep beams reinforced with different amounts of FRPs. The results showed that the Proposed STM has yielded accurate and consistent results, while other design provisions have underestimated the shear strength considerably. Furthermore, a parametric study was also conducted to check the ability of the proposed STM to represent the effect of changing the various parameters that control the shear strength.