Experimental Study of the Steel-Concrete Connection in Hybrid Cable-Stayed Bridges

A new steel-concrete connection with Perfo-Bond Strip (PBL) connectors for a hybrid cable-stayed bridge was adopted and introduced. Push-out tests of the PBL connectors were performed to evaluate the shear capacity of perfobond ribs in steel-concrete connections. Test results revealed that the shear strength of a perfobond rib in a twin configuration is about 80% of that of a single independent perfobond rib. To investigate the safety and reliability of the proposed connection from a practical perspective, a model test with a scale of 1:2 for the joint of the hybrid girder was carried out on site. During the test, stress distribution, crack resistance ability, and relative slip between concrete and steel were measured carefully to investigate the mechanical performance, force transmission, strength, and stiffness of the steel-concrete connection. The test results revealed that concentrated stress at the loading section in steel girders can be reduced and transferred uniformly through the joint to the concrete sections by a combined axial and shear force transmission mode with the help of bearing plate and multiple parallel perfobond ribs. The findings from the tests and analyses are considered to be of special significance to the design and construction of steel-concrete connections in hybrid cable-stayed bridges.