The standard SN 640 451 „lining systems and bitumen containing layers on bridges with timber roadway slabs“ was published in 2009. This standard deals for the first time with system structures for sealing and bitumen containing layers (asphalt pavement) on timber bridges. This standard only applies to sealing systems without bond as there was not enough knowledge and experience in system structures with bond at that time. The influence of changing timber moisture content in roadway slabs was insufficiently known. Furthermore liquid synthetic sealant couldn’t be considered.
Since structures of road bridges with shear coupling in particular have become routinely, fundamental research and requirements will be established in the planned research project.
The project constitutes the consistent continuation of a research project called “asphalt surfacing on timber bridges”
(
http://www.bafu.admin.ch/wald/01234/01238/15631/index.html?lang=de) implemented by BFH and other parties of the advisory commission and financed by the Federal Department of Environment. The development of initial system solutions for bituminous roadbed on road bridges with timber structures has already been taken. Findings, materials and structures elaborated for massive bridges based on VSS 2006/509 initial project “lining systems and bituminous layers on concrete bridges” are tested for their applicability for timber bridges.
