Ductility and stiffness of shear studs in solid concrete slabs for design according to EC4

The ductility and stiffness of shear connectors play an important role in both the ultimate and serviceability limit state design of steel–concrete composite structures. This paper presents empirical models for predicting the slip capacity, elastic slip, and stiffness of headed shear studs in solid concrete slabs determined using the resistance model from the second generation of Eurocode 4 (prEC4) and a design model previously developed by the present authors (SRD2). The empirical models, which are functions of stud shank diameter, concrete compressive strength, stud height-to-diameter ratio, concrete type, and slab reinforcement position relative to the stud head, were developed using regression analyses of a comprehensive database of 180 test results compiled in the study. The effects of the shear connection parameters on their ductility and stiffness were evaluated. The characteristic values of the elastic slip, slip capacity, and shear stiffness were determined following the EC4 and EC0 requirements. Parameters of the shear stud connectors needed to achieve Ductility Categories D2 and D3 from prEC4 were determined based on the developed models. The shear stiffness of the studs of different diameters and heights in normal and lightweight concrete slabs was also evaluated. The developed models outperform existing models based on the presented comparisons. This study provides important information on the ductility and stiffness of shear studs embedded in solid concrete slabs based on comprehensive test data covering a wide range of design parameters that may occur in practice, thereby contributing to the economy and safety of steel and concrete composite structures.