RESEARCH ON PUNCHING SHEAR AND BENDING BEHAVIOR OF ULTRA-HIGH PERFORMANCE CONCRETE SLABS

Ultra-high performance concrete (UHPC) bridge deck has good prospects for engineering application. In order to study the punching shear and bending behavior of bridge deck under wheel loading, a series of UHPC slab tests were designed. The effects of slab thickness, cover thickness, reinforcement ratio and loading area on the punching shear and bending behavior of the slabs were studied. The failure modes, the deflection, the strain distribution and the ductility of different specimens were analyzed. And the calculation methods of punching shear capacities of UHPC slabs were proposed. The test results show that the failure mode includes punching shear, flexure and mixed punching-flexure mode. The stiffness, the punching capacity, the ductility and the energy absorption capacity of the UHPC slabs are much higher, compared with the C50 concrete slab. And the punching shear capacity of UHPC slabs increases with the increase of slab thickness, with the decrease of cover thickness and with the increase of loading area. Verified by the test data, the calculated values of punching shear and bending bearing capacity are in a good agreement with the test values.