Structural Behavior of Floor Systems Made by Floor Plates—Mechanical Model Based on Test Results

In daily engineering practice, the execution of concrete slabs by the mean of precast floor plates is seen as a common and reliable way to create massive slabs. In the last few decades, however, there has been an evolution to flat slabs and other uses where important bending moments must be transferred over the joints between the floor plates. For this kind of application, there is a lack of knowledge and experimental evidence based on large-scale tests to define accurate failure and design models. In this work, a comprehensive overview is given of 20 large-scale tests and some additional tests to support the findings and observations. It is confirmed that a purely bending-based design of the joints delivers reliable results, but some conditions are set; first, the maximum distance of the lattice girder to the joint may not exceed 400 mm without voiding elements. Second, only a 95 mm distance must be respected with voiding elements or additional protruding reinforcement must be applied. Attention is also given to how the system works when the major components—adhesion, mechanical interlock, and friction—are missing at the interface. Finally, repair possibilities are discussed and how they should be designed.