Mechanical performance of <scp>UHPC</scp> waffle plate under local loading: An experimental study

Abstract The present paper studies the punching shear behavior of the ultrahigh‐performance concrete (UHPC) waffle bridge deck. For this purpose, the punching failure tests were conducted on 11 UHPC waffle plates, with the structural form and loading plate area serving as the primary test variables. The objectives are to obtain the load–deflection curves and cracks at the bottom of each specimen. Additionally, the impact of these parameters on the punching shear performance of UHPC waffle plates was systematically analyzed. The applicability of existing formulas for calculating the punching shear capacity of UHPC waffle plates was also evaluated. Based on the test and calculated results, a formula for calculating the punching shear capacity of the UHPC waffle plate, considering the effect of the stiffening rib width, was proposed. The test results showed that the critical crack caused by punching failure in the specimen extends from the center of the loading position to the periphery along the diagonal direction. This critical crack gradually forms two closed annular cracks, and the final failure shape of the plate bottom resembles a “pot bottom” shape. It was observed that the punching shear capacity of the waffle plate is positively correlated with the increase in the stiffening rib width and the loading plate area. Furthermore, the newly developed formula was successfully validated against the experimental data from this study and other literature, demonstrating its potential for engineering applications.