Crack Resistance of Steel–Concrete Hybrid Joint between Concrete Girder and Steel–Concrete Composite Girder in Long-Span Cable-Stayed Bridge under Hogging Moment

Abstract

The steel–concrete hybrid joint (SCHJ) between a concrete girder and a steel–concrete composite girder in a cable-stayed bridge has a high risk of cracking under a hogging moment. This study investigated the crack resistance of the SCHJ. Based on a specific bridge, a half-scale SCHJ specimen was designed and tested. A particular loading setup was developed to reproduce the actual loading conditions of the SCHJ. The crack developments and strain distributions of the SCHJ specimen were observed. The SCHJ with fully infilled concrete cracked earlier than the composite girder. A numerical model was developed using the ABAQUS software version 6.14, and the results obtained by this model were in good agreement with the experimental results. The crack development laws of the concrete deck at typical sections in the SCHJ and composite girder in this bridge were derived. An analytical model was proposed to describe crack development in the SCHJ and composite girder. An SCHJ with partially infilled concrete was proposed to improve the crack resistance of the SCHJ compared with the composite girder, and design recommendations were provided for the novel SCHJ with partially infilled concrete in this bridge.