Shear performance and dimension rationalization study on the rubber sleeved stud connector in continuous composite girder

Abstract

Wrapping rubber sleeve around a stud shank near the root makes a low level of shear connection between the steel girder and concrete slab in a composite girder. It helps to reduce the concrete tensile stress and steel compressive stress in the hogging moment region. However, the specific mechanical effects of the rubber dimension and modulus on the connector performance have not been understood, which hinders the application in practice. To this end, 15 push-out tests on studs wrapped with rubber sleeves were conducted for the investigation. And a push-out parametric analysis with damage plasticity models was executed for dimension rationalization. The test results showed an obviously lower stiffness and larger bending deformation of rubber-sleeved stud as compared with a normal stud, while the strength varied little. The analysis results showed that the efficient rubber thickness and length for a 22 mm-diameter and 220 mm-high stud could be 4 mm and 50 mm in terms of the stiffness reduction extent. It also showed an obvious stiffness reduction occurred when the wrapping material modulus was 10% lower than concrete. Furthermore, the connector stiffness effect on the stress distribution along with a continuous composite girder was analyzed and quantified, showing a 39% reduction of concrete slab stress in the hogging moment region and a 13% increase of steel stress on the top flange.