Longburn Rail Overbridge

The Longburn Rail Overbridge on State Highway 56 required structural strengthening to increase its load‑carrying capacity for High Productivity Motor Vehicles (HPMVs). To achieve the required performance upgrade, an external post‑tensioning solution was selected using Freyssinet’s proprietary 1R15 anchorage system. This system is specifically designed for reinforced concrete structures—particularly thin elements—where additional prestressing is needed without major reconstruction. The strengthening involved installing external strands along the concrete girders, deviated at points of contraflexure and anchored at the girder supports, allowing the prestressing force to be efficiently transferred into the structure.