Study on the process of punching shear failure of reinforced concrete slabs

Loading tests on small-sized reinforced concrete slabs were conducted to clarify the process of punching shear failure. The test parameters included the thickness and reinforcement ratio. The strain of concrete and deflection relative to the loads were measured, and the internal cracking was recorded. It was found that circumferential strain on the top surface of slab monotonically increases up to the ultimate stage, whereas radial strain changes from compressive to tensile as the load increased. The observation of the internal cracking revealed that diagonal cracks leading to the ultimate failure abruptly propagate just before the ultimate load.