Today, steel and reinforced concrete bridges have to withstand extreme loads: they are exposed to constantly changing weather conditions and bear enormous loads. In order to reach the targeted duration of use of 40 years and satisfy the corrosion protection requirements defined in DIN EN ISO 12944 the steel components utilised must be provided with effective protection.
|Cup spring dampers||Post-tensioning systems||Concrete screws an anchoring|
Cup spring dampers are always used where the aim is to transfer and dampen dynamic loads – for example in the stabilisation of suspension cables for arched bridges. A special corrosion protection is elementary to ensure longevity and functionality.
Post-tensioning systems are used, amongst other applications, in the transverse prestressing of bridges and pier heads and are used in both the construction of new bridges and the retrofitting of existing bridges. As they are exposed to unusual pressure and weathering conditions, protection against corrosion is especially important.
Fastening elements in bridge building have a safety-relevant factor: they secure restraint systems, noise protecting walls, retention and shear reinforcement and therefore generally need to achieve the highest corrosion resistance categories.
Effective corrosion protection in bridge building is provided by the zinc flake coating developed by DÖRKEN. The technology approved by the Deutsches Institut für Bautechnik (DIBt) for the C5-M field can be applied in very thin coats of 8-12 µm at very low annealing temperatures (from 180°C). In addition, no hydrogen is generated in the application process - an advantage for high-tensile steel in particular. In combination with a suitable topcoat a high degree of cathodic protection and specific functional characteristics such as coefficients of friction or UV resistance can be achieved.