Behaviour and design of shear connectors in composite slabs at elevated temperatures

• Experimental results of push-out tests at elevated temperatures
• Structural response of connectors in composite slabs at elevated temperatures
• Design capacities of shear connectors at elevated temperatures

This paper presents an extensive experimental and numerical study aimed at the evaluation of the thermo-structural response of shear connectors embedded in composite slabs with steel sheeting perpendicular to the steel beam, with particular focus on open-trapezoidal profiles. Six push-out tests were carried out at different levels of temperature. A three-dimensional finite element model was developed in Abaqus and its accuracy was validated against the experimental measurements collected as part of this study. The model was then used to perform a parametric study to gain insight into the structural response at different temperature levels. These results, together with experimental data available in the literature, were used to evaluate the ability of European guidelines to predict the capacity of shear connectors at elevated temperatures (when embedded in composite slabs with the profiled sheeting perpendicular to the steel beam). It was shown that predictions from Eurocode 4 provided conservative estimates of for shear studs' capacities. For this purpose, a new design equation was proposed to calculate the degradation factor defining the resistance of shear connectors for different levels of temperatures.