Improvement of Steel Bridge Joints using Link Slabs

Abstract

Traditional steel bridge construction commonly uses expansion joints to account for structural movements. However, these joints are prone to deterioration over time due to water and debris infiltration, leading to high maintenance costs and shorter service life. This study explores the use of Link Slabs as an alternative solution to improve bridge performance by replacing expansion joints. The proposed system incorporates a debonded zone to reduce internal stress and utilizes Ultra-High-Performance Concrete (UHPC) with a compressive strength of 100 MPa, which provides superior mechanical properties and post-cracking ductility. Structural analysis of a typical steel bridge with a 25-meter simple span shows that implementing UHPC Link Slabs allows for the continuous connection of up to four spans, effectively extending joint spacing to 100 meters. The results from the structural analysis program indicate that the use of Link Slabs significantly reduces overall bridge deformation under live loads and thermal effects, thereby enhancing structural performance and reducing long-term maintenance costs. However, the increased continuity may result in higher loading on existing bridge bearings, which may necessitate the reinforcement or replacement of certain substructure elements.