Many short-span highway bridges are constructed using precast concrete beams. The range of precast beams has changed over the decades with the introduction of new designs and construction types. However, for a range of reasons, some of the older bridges are in need of repair, retrofitting or replacement. They also tend to lack the required capacity, as new design standards have introduced higher traffic loading demands. This paper presents the retrofitting of a highway bridge with a span made of precast concrete box beams and cast-in-situ overlay. Extensive damage to the asphalt pavement on the bridge required continual repair. The buried expansion joints were damaged, and there were doubts as to the condition of the deck waterproofing membrane. A design was drafted and repairs to the bridge were carried out, which included the removal of expansion gaps and construction of a precast concrete beam deck which was to be integral with the abutments. As part of the retrofitting works, the deck waterproofing was replaced with new asphalt layers on the bridge. Making the bridge deck integral with the abutments made it possible to achieve a smooth pavement surface without expansion joints and to improve the riding quality. Verification of the bridge deck resistance, by adopting the numerical load distribution approach, allowed the bridge bearing capacity to be increased to the highest traffic loading.

Highway Bridge, Precast Concrete Beams, Integral Bridge, End Diaphragm