Timber block beam bridges

Block beam cross-sections are optimal for span widths of 15 m to 35 m

The progress in the area of the bonding technology enables large-format components. It was on this basis that this new type of bridge was designed, which differs from a conventional deck bridge because the supporting structure consists of a solid block. The higher structural potential of the bonding is taken full advantage of. This means that leaner cross-sections can be chosen that offer visual benefits. At the same time, the block bonding also offers a free design. It is possible to create curved components for either the plan view or elevation.

Attributes of block beam bridges:

  • variation of the deck bridge with block-bonded main girders
  • block bonding enables attractive cross-section versions and architecturally appealing design possibilities
  • The roadway surface runs over the covered main supporting structure
  • Design of the road surface can be chosen freely in the form of solid timber decking, GRP decking, as a mastic asphalt surface or as large-format natural stone slabs / pre-cast concrete parts

Protected main supporting structure

Structural timber protection is the key to the longevity of a timber bridge. Structural timber protection intends for all structural timber components to be completely protected. In this respect, the following steps are taken into consideration: Installation of technically dried timber with a timber humidity of 12% in order to prevent insect infestation, protection against weathering, ingress of moisture, UV rays due to the installation of projections and skirting in the design as well as good air circulation to encourage drying out. Constructions designed in this way satisfy the requirements of protected timber bridges pursuant to DIN EN 1995-2 NA. This means that loss events are prevented and maintenance costs are minimised, and the use of timber preserving chemicals can be reduced and/or avoided. Structures protected according to DIN EN 1995-2 have a service life of 60 - 80 years*.

* Source: Redemption amounts calculation regulations - ABBV, BMVBS, status 2010 and study of DGfH 2006

Advantages of the block beam bridge:

  • optimum cross-section use for span widths of 15.0 m to 35.0 m.
  • Cost-effective alternative to steel or concrete bridges, also with high loads
  • Streamlined construction height
  • Optimum timber protection with all versions of road surface
  • side railing connection possible