Coating the cables at bridges can be particular challenge. The ropes of the Speyer bridge, Germany were preserved by the Sika® Cable System. The SikaCor® EG System was used for the pylon and the railings and the Sika® Cable System for the ropes. The system applied to coat the cable-stayed bridges is now recommended by the Federal Highway Research Institute (BASt) of the German Federal Government. Partial restoration provides system durability of over 15 years. With a full refurbishment, more than 25 years can be achieved.
The Speyer Bridge spans the Rhine three kilometers northeast of the center of Speyer. It is located 100 km south of Frankfurt, Germany. The flyover with a cable-stayed bridge in the river segment is part of Federal Highway 61 and is located between the junctions Speyer and Hockenheim. The bridge section is 758 meters long and has two lanes plus an emergency lane in each direction. It was constructed between 1971 and 1974.
Twelve kilometers of steel cables
In 2008 the blue, 70-meter-high pylon was restored with corrosion protection. Work began in 2011 on corrosion protecting the reddish, 15-centimeter-thick steel cables. Before the new coating can be applied, the old one has to be removed from a total of twelve kilometers of steel cable, for which purpose they need to be encased. This comprises constructing two frameworks and, depending on the rope height, installing a closed workspace, creating the impression of a shoebox.
Application of new anti-corrosion coating
When the old anti-corrosion coating is removed, the new coat is applied to the ropes. Weather conditions have a considerable impact on application and drying times. The work higher up was affected by the heavy traffic, which caused considerable vibration. To create a more secure working environment, a permanent speed camera was installed to enforce a speed zone of only 60 km/h.
Full service and supervision on site
Sika Germany’s application consultants performed regular site supervisions. Additional controls were carried out at the railings, the pylon and the ropes. Bonding tests were conducted regularly for the construction supervisor.
Low-solvent and low VOC loads
The customer opted for Sika® Cable System to preserve the ropes because of the high quality of the material, but also for the service and site supervision provided by Sika. The SikaCor® EG System was used for the pylon and the railings and the Sika® Cable System for the ropes. The low-solvent systems which were used during the entire refurbishment process have low VOC loads, which is of particular importance.