Longitudinal shear resistance of composite slabs. A new model

A new model is presented describing the physical behaviour of shear connections in composite slabs. The model recognizes the improved shear resistance over the supports of shear connections in composite slabs. The application of the new model is related to the Partial Shear Connection method as available in the ENV 1994-1-1 (Eurocode 4). The model should be considered as a first step towards a design model based on obtained insight into the physical behaviour of connections in composite slabs. INTRODUCTION Analogy exists between embossed profiled sheeting in steel-concrete composite slabs and reinforcement in reinforced concrete slabs, as illustrated in Figure 1. Due to the presence of a shear connection between the sheeting and the concrete the sheeting acts as reinforcement for the composite slab. Since the sheeting is not embedded in concrete and behaves flexible due to its limited thickness, the strength and stiffness of the connection is significantly smaller. Therefore, mechanisms describing longitudinal shear in composite slabs are based on the displacement and deformation of the sheeting rather than the cracking and crushing of concrete as present in shear connections between reinforcement bars and concrete in reinforced concrete. Figure 1: Shear connection reinforced concrete versus composite slabs