Punching Shear Behavior of Restrained Reinforced Concrete Slabs

Punching tests on 12 restrained reinforced concrete slabs are re­ ported in this paper. The slab panels were supported and restrained on all jour sides by edge beams. The influence of the degree of edge restraint, percentage of steel reinforcement, and span-depth ratio of the slabs on the structural behavior and punching shear capacity of the slabs was investigated. The punching shear strengths observ.ed were much higher than those predicted by Johnson's yield-line the­ ory, BS 8110, and ACI 318. The enhanced punching shear capacity was a result of compressive membrane action caused by restraining action at the slab boundaries.