Bridges

At 2582.6 m in length, Melbourne's West Gate Bridge is the second longest bridge in Australia. Completed in 1978, the bridge comprises a cable-stayed steel box girder, with two end concrete sections of similar design. Due to Melbourne’s rapidly growing traffic demand, an increase in the capacity of the bridge was necessary. The winning proposal was to augment the number of traffic lanes by one each way, increasing the total from eight to ten. This additional torsional loading on the bridge added, required large areas of the pre-cast concrete sections to be retrofitted with externally bonded, carbon fibre (Fibre Reinforced Polymer, FRP) strengthening. Whilst ultimately being the largest FRP project in the world, clever early design, detailing and planning decisions, resulted in a number of innovations, which ultimately delivered major savings to the project. This paper highlights the case study of the West Gate Bridge and discusses some of the issues related to optimized design solutions and latest research on anchorage details. It also explores application topics including preparation techniques, environmental conditions and quality assurance issues, dealing with high strength concrete elements, strengthened with FRP systems.