Durchstanztragverhalten von Einzelfundamenten mit einer neuartigen Durchstanzbewehrung

Punching shear behaviour of footings with a new punching shear reinforcement

Due to more compact dimensions and soil-structure interaction, footings and ground slabs achieve significantly higher punching shear capacities than flat slabs. Since the inclination of shear cracks is much steeper in footings, punching shear reinforcement elements with inclined bars seems to be more efficient than vertical bars. On the basis of previous experimental investigations on footings with punching shear reinforcement, a new punching shear reinforcement element with inclined bars was developed.
To evaluate the efficiency of the new punching shear reinforcement element, a total of seven tests on footings with uniform soil pressure and a failure within the shear-reinforced zone was conducted. The tests were planned considering the results of a systematic test series on reinforced concrete footings without and with stirrups as punching shear reinforcement. The main parameters investigated in this test series were the shear span-depth ratio, the specific column perimeter and the number and layout of punching shear reinforcement elements. The comparison of the results of the new test series with the previous test series and the punching shear capacity without punching shear reinforcement according to DIN EN 1992-1-1+NA(D), respectively, proves a significant increase in punching shear capacity with the new punching shear reinforcement.