3 Danish hybridbridges

3 Danish hybridbridges

There is a growing awareness of the multiple benefits of GRP composite, and one application where GRP can make a decisive difference is as a surfacing material for pedestrian and cycle bridges. The GRP can be customized to the bridge specifications required - in terms of both strength, rigidity and weight.

A hybrid solution combining wood, steel and GRP composite provides a competitive alternative to conventional concrete or steel structures. So competitive that international consultants at NIRAS declared GRP to be the 'X factor' in a recent project where Fiberline was a supplier. In this newsletter you can read about two topical examples of pedestrian and cycle bridges in which the solution chosen was a hybrid bridge with a GRP deck.


Two cycle bridges

In October 2015 a cycle path incorporating two bridges was opened in Middelfart in central Denmark. Supplied by Danske Woodways, both bridges consist of a hardwood substructure supporting a black-painted bridge deck made of Fiberline Heavy-Duty (HD) plank. Among other things, the elasticity of the GRP composite enabled the bridges to be provided with transverse drains. Both bridges were assembled on site in just a few hours. The HD planks are prefabricated elements which are lightweight and can easily be lifted into place and machined on site.


Pedestrian and cycle bridge over Copenhagen station

The existing concrete bridge crossing the railway at Copenhagen's Husum Station needed to be demolished for safety reasons. The contract for a replacement bridge was awarded to NIRAS, with installation causing minimal disruption to train traffic. The project called for a bridge that was both strong and lightweight and could also be assembled quickly. In this case the solution chosen was an FBD 300 (Fiberline Bridge Deck) made of GRP composite with a steel substructure resting on the existing concrete foundation. HSM Stålindustri built the bridge, which in addition to being lightweight also saves maintenance expenditure as GRP composite does not crumble, rot or corrode.

Breakthrough for hybrid bridges

Besides the cases described above, GRP decks from Fiberline have in recent months also been chosen for other bridge projects in Denmark: a cycle bridge in Haderslev, a dual pedestrian and cycle bridge for Femern A/S in the port of Rødby, and both an inspection bridge and road bridge in Vejen.


Fiberline's Technical Solution Manager, Christian Scholze, explains that hybrid solutions are a popular choice for small bridges where light weight, minimal maintenance and fast installation are demanded:

"With a hybrid bridge you get an extremely attractive solution that unites the best qualities in each material at a competitive overall price. For example, you can take the rigidity of steel or wood and combine it with the durability of GRP composite. This is the solution we see frequently. Fiberline supplies a corrosion- and maintenance-free deck made of GRP composite that provides a watertight surface and protects the substructure, whether it's made of wood or steel”, says Christian Scholze.