Title: Maximum punching shear capacity of footings with new punching shear reinforcement elements

Author(s): Dominik Kueres, Marcus Ricker, Josef Hegger

Publication: Symposium Paper

Volume: 315

Issue:

Appears on pages(s): 167-186

Keywords: Reinforced concrete footings, punching shear, shear span-depth ratio, specific column perimeter, punching shear reinforcement, maximum punching shear capacity

DOI:

Date: 4/1/2017

Abstract:
Due to more compact dimensions and soil-structure interaction, footings and ground slabs achieve significantly higher punching shear capacities than flat plates. Since the inclination of shear cracks is much steeper in footings, punching shear reinforcement elements with inclined bars seem 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. In a first experimental campaign, seven tests on reinforced concrete footings with the new punching shear reinforcement elements and a failure inside the shear-reinforced zone were performed. Based on the results of the first test series, a second experimental campaign was conducted to investigate the maximum punching shear capacity with the new punching shear reinforcement. The main parameters investigated in this test series were the shear span-depth ratio, the ratio of column perimeter and effective depth, the concrete compressive strength, and the layout of punching shear reinforcement. The comparison of the failure loads of the specimens with the punching shear capacity without punching shear reinforcement according to ACI 318-14 shows a high efficiency of the new punching shear reinforcement, especially when compared to vertically arranged reinforcement elements like stirrups and studs. The results of the second test series are presented in this paper.