Punching Shear Strength of Simply Supported Ferrocement Slabs

The results of punching shear tests on 31 square ferrocement slabs are reported in this paper. The slabs were simply supported on all four sides and tested under a central concentrated load. The parameters investigated include the width of square loaded area w, mortar strength f′c, volume fraction of reinforcement Vf, depth of slab h, and the effective span ℓ. All slabs failed first in punching without total separation, and then exhibited a second peak in the load-deflection history. Both cracking load and punching shear load increased with an increase in w, Vf, f′c, or h, but decreased as ℓ is increased. The critical perimeter for punching shear failure was found to be located at a distance of 1.5h from the edge of the loading plate. Based on the present test data as well as those available in the literature, an equation has been proposed for predicting the punching shear strength of ferrocement.