Static and Fatigue Behavior of the Stud Shear Connector in Lightweight Concrete

The lightweight concrete has been increasingly applied in the civil structures for the lightweight merit and the strength improvement. Concerning the composite bridges, the interlayer shear connector is actually quite important to achieve the composite action whereas the static and fatigue mechanism understanding of it in the lightweight concrete is not enough. Therefore, a series of static and cyclic push-out tests and analysis on the frequently used stud connector, together with the discussions on the existing results in literatures, have been executed. In this study, the stud shank diameter and height were 19 and 150 mm, respectively. The results showed that the lightweight concrete tended to lower down the stud static stiffness due to the lower modulus. Meanwhile, the stud in the lightweight concrete was found to be with a lower fatigue life. And some of the current civil codes cannot guarantee the corresponding safe fatigue life estimation, such as that based on the Japanese Standard Specification for Hybrid Structure may experience an overestimation.