Load-bearing behavior and efficiency of layered two-way slabs

Two-way spanned steel reinforced concrete floor slabs are found in many buildings. They demand large quantities of material due to their comparatively large dimensions. If the material and thereby the weight could be reduced, natural resources and energy would be saved. In order to reach this goal, the bearing behavior of two-way regular concrete floor slabs was analyzed and subsequently cross-sectionally optimized. This resulted in the creation of two- and three-layer cross sections, consisting of regular concrete and a lightweight foam concrete. This paper describes the general load bearing behavior of layered twoway concrete slabs on the basis of experiments, the failure modes that need to be considered and the suitability of calculation models, which are anchored in the actual European code of concrete structures. The analyses indicate that the chosen approaches lead to efficiently bearing slabs with a weight reduction of about 15 % in comparison to regular concrete slabs.