Static performance and failure mechanisms of a rubber-stiffened steel plates with rapid-hardening concrete for sustainable bridge expansion joints retrofitting

Given the vulnerabilities, complexity, and repair challenges associated with traditional bridge expansion joints, this study proposes a sustainable continuous deck structure utilizing rapid-hardening concrete and rubber-stiffened steel plates to eliminate conventional joints. To evaluate the static performance of this structure, compression test and finite element analysis are conducted. The results indicate that the primary failure mode of the continuous structure, composed of rubber-stiffened steel plate, is delamination between the steel plate and the rubber layer. As the load increases, the rubber layer deforms, causing cracks in the concrete at the bottom anchorage zone and ultimately leading to the rupture of the rubber layer. Under the static load of a standard vehicle, the continuous structure meets the required bearing capacity. For practical application, it is recommended that the stiffened steel plate thickness exceed 10 mm to reduce stress and satisfy structural demands. Analysis of an actual bridge under moving loads shows that neither the stiffened steel plates nor the rubber layer reach their yield strength during the continuous construction of the abutment, ensuring the structure meets capacity requirements. The findings provide valuable insights for the design of jointless bridge structures. • Identifies interfacial delamination as the dominant failure mode in rubber-stiffened steel plate bridge decks under static loads. • Validates ≥10 mm steel plate thickness for stress mitigation, ensuring compliance with vehicle load requirements. • Reveals failure progression from rubber deformation to concrete cracking and rupture via FEA and compression tests. • Confirms yield-limit compliance under simulated dynamic loads.