Many existing box girder bridges are currently being retrofit with FRP composite materials to achieve greater flexural,shear and torsion strength in order to meet the demand of todays escalating traffic loading.The technical challenges involved with such bridge retrofit projects will be investigated though a case study of the Westgate Bridge project which is one of Melbourne,Australias most iconic and important links in the transportation network and is depicted in figure 1.Efficient FRP anchorage solutions developed specifically for this project,involved the use of bidirectional fibre patch anchors have resulted in increases in fibre utilization levels resulting in reduced material requirements and more timely implementation.The anchorages were developed in a further experimental study to investigate the size effect of patch anchors for wide applications in the increasing number of projects of this nature worldwide.