Distribution of forces in composite concrete slabs between the joint and the reinforcement anchored on the support

In general composite concrete slabs consist of two concrete layers: a prefabricated reinforced floor plate and an additional layer of concrete cast in-situ. The interaction of the two layers is based on the transmission of shear stresses in the joint surface. Transmission is possible through the appropriate shaping of the joint surface and the use of vertical reinforcement in the form of truss. The results of tests for different composite concrete slabs presented here suggest that the interaction of the two concrete layers may depend on the suitable anchoring of the bottom reinforcement in a ring beam. The full anchoring of bottom reinforcement allowed to obtain the full load bearing capacity of the composite slab with no possibility of bond stress transmission in the joint surface. The distribution of forces between the joint surface and the bottom reinforcement anchored in the ring beam depends on the shape of the joint surface.