Experimental Study on Shear Behavior of Prestressed Concrete Deep Beams with Draped Tendons

摘要

Two simply supported deep beams were tested, one with draped prestresssing tendons and the other without for reference. Shear behavior and the prestressing effect were focused on. The test results showed that deep beams with the longitudinal reinforcement ratio of a normal amount were inclined to fail in flexural-shear, and the prestressing could greatly increase both the cracking load and the shear strength. Beside, the Modified Strut-and-Tie Model (MSTM) and the sectional design method from China Code (GB02) have also been adopted for predictions. The comparisons indicates that the MSTM can not only well predict the shear strengths of deep beams, but also well account for the prestressing effect, while the sectional design method seems so conservative due to its not properly considering the shear mechanism of deep beams. It can be concluded that the MSTM is capable of predicting the shear strength of PC deep beams with draped tendons and thus can be employed in practical designs.