Punching shear behavior of lightweight fiber reinforced concrete slabs

The ultimate behavior of thin reinforced concrete structures, such as slabs, can be governed by punching due to point loads. This premature brittle failure mode can occur in bridge deck slabs, often subjected to severe conditions of loads concentrated in small areas, and characterized by a reduced thickness. In this kind of structures, a proper punching reinforcement is not applicable, but the local and global behavior can be improved by the addition of short fibers. Three full-scale slabs, simulating bridge decks, were tested in the Laboratory of the University of Rome Tor Vergata, to investigate the effect of lightweight fiber reinforced material on the punching shear resistance. Furthermore, ashes coming from the combustion of Municipal Solid Waste (MSW), with pozzolanic reaction, were added to the concrete mix. The obtained results are presented, discussed and compared with the MC2010 provisions.