Experimental and numerical investigation on the behavior of concrete sandwich slab panel for a structural system

This paper proposes a simplified methodology based on a concentrated plasticity model to develop numerical analysis of concrete sandwich slab panels for structural systems. Also, a proposal for the determination of experimental damage and its evolution within concrete sandwich panels is formulated. To validate the proposed methodology, an experimental study was carried out on full-scale slab panels to analyze the flexural behavior. Eight specimens were subjected to three- and four-point bending tests. A cycle loading protocol with unloading up to zero load was performed. These specimens, constructed with either one or two joined panels, were used to assess the group action. Mechanical properties for structural analysis—such as strength, stiffness, degree of composite action, and effective moment of inertia—were determined. The tested specimens exhibit significant stiffness degradation, indicating a notable evolution of damage even at small plastic displacements. The proposed methodology proves to be effective and reliable for predicting the behavior of concrete sandwich panels under bending moments. The numerical simulations performed show an adequate description of slab panel behavior until the ultimate load, regardless of its simplicity.