Investigation of longitudinal shear strength in concrete slabs with profiled steel decking

Composite slabs with profiled steel decking are widely used in floor carrier systems of steel structures. Various combinations of steel with high tensile and ductility properties and concrete with high compressive strength and corrosion resistance are used and applied worldwide in steel and concrete composite structures. Composite slabs have many advantages, such as ease of application, good performance against fire, no mold required, and high-bending capacity. But there are no analytical formulas for calculating the strength of composite slabs. Therefore, this study had the aim to simulate a numerical model which could reflect the most realistic behavior. The most significant attention was given to model the interaction between steel deck and concrete to achieve this aim. Because one of the most critical limit values to be considered in this type of slab design was the longitudinal shear strength. The interaction was seen as two stages, where the first stage was a work of chemical bond, the second stage was the influence of mechanical and frictional factors. The two most important factors as shear strength in first slip and mechanical interlock were assumed. Using the Variable Engagement Model allowed calculating the first slip for the SFRC slabs and using it in the interaction model of composite slabs. The SFRC slabs showed significant and consistent improvements in the overall strength and the load at first slip compared to the plain concrete slabs. The improvement in the shear-bond behavior afforded by the steel fibers at the steel-concrete interface has been quantified. In the end, composite slabs test results that were made before were compared with the results obtained in numerical models.