Nonlinear Analysis of the Creep Behavior in Ledge Girders Strengthened with Internal Prestressed Concrete Jacketing

Abstract

Structural components of historical bridges, particularly reinforced concrete ledge girders, often experience deterioration after extended service periods due to high load demands and environmental fluctuations. This deterioration results in a reduction in load-carrying capacity and the development of cracks. To address these issues, internal prestressed concrete jacketing has been adopted as a strengthening technique to enhance structural performance and extend service life. This paper focuses on the nonlinear analysis of the creep behavior of RC ledge girders that have been strengthened using this method. A three-dimensional nonlinear finite element analysis (3D NLFEA) was conducted using ATENA Science software to investigate deformation and crack propagation under sustained long-term loading. The study also considers the shear transfer capacity at the interface between the existing and newly applied concrete, under varying bond conditions. The analysis results reveal that concrete creep behavior plays a critical role in the long-term performance of strengthened ledge girders. Although the strengthening method significantly improves the initial load carrying capacity, long-term effects indicate that creep leads to progressive deformation and increased deflection over time. The findings from this study contribute to assessing the effectiveness of the strengthening technique and provide engineering insights to support the rehabilitation of aging bridge structures.