Bridge over river Zrmanja in Obrovac

The bridge in Obrovac was built from 1950-1952, on the foundations of the previous bridge demolitioned at the end of the World War II. The span construction consists of four continuous classically reinforced girders with the upper reinforced concrete deck. The central span is 42.2 m and both overhang spans are 13.6 m. After 50 years of service, a bridge inspection was made. Stone lining of the piers and abutments in the water level change-zone of river was significantly damaged. At dilatation points were cracks in the asphalt and 5 cm delevelling on the pedestrian lanes. Based on the visual inspection of the bridge concrete structure and sample laboratory tests it has been concluded that the quality of concrete is very good. Damages due to rebar corrosion were limited to the outside surface of the external girders and pedestrian lanes. Based on the bridge inspection results, a design for bridge rehabilitation was developed, and the rehabilitation works were done. The outside girder concrete was reconstructed in the way that the rebar protective layer was replaced with polymer modified special concrete. The old cornice was replaced with the new one where additional rebar was installed. Underview of the pedestrian lanes was also reconstructed. The existing steel curb was replaced with the new one at the top curved towards the pedestrian lane. The existing asphalt pavement and hydro-isolation were replaced with a single overlay of fiber reinforced polymer modified concrete, bonded to the exsisting concrete deck, and was also the bridge’ s final surface. During the repair works the traffic was ongoing, alternatively, on a single traffic lane.