Study on the ductility of open‐rib and re‐entrant composite slabs

Abstract

Composite slabs with profiled steel sheeting and cast‐in‐place concrete are a conventional structural flooring system worldwide. The partial connection method (PCM) is a design method limited to slabs showing a ductile longitudinal shear failure. The ductility is defined in Eurocode‐4 in terms of additional strength after certain initial slip is produced, regardless of the steel sheet profiling shape. This article shows that the slip behavior is significantly different depending on the shape of the sheeting profile. On the one hand, the slip magnitude in reentrant slabs can be large enough to drive the two materials to their yielding stresses; on the other hand, in open‐rib profiles, the slab failure is due to the vertical release of the concrete, when the slip overpasses certain geometric limit. This failure mode is generally produced much before the materials reaches their yielding stresses. This finding is consistent with both the experimental and FEM results carried out in this study.