SWISS scientists are developing plastic girders for use in cable stayed bridges.
Boffins at the Swiss Federal Laboratories for Materials Testing and Research have produced a cable stayed bridge with a glass fibre-reinforced polymer support girder as part of an ongoing project to examine the dynamics of light weight structures.
The project, headed by Dr Daniel Gsell, aims to create an experimental research platform that will shed light on the use of GRFPs in bridges.
He claimed that most modern designs for bridges favour large spans with slender and lightweight structures. This leaves them increasingly prone to fatigue caused by vibrations.
The EMPA team has built a scale model of a lightweight cable stayed bridge in order to study the effects of vibrations on full-size structures.
It is constructed using five pultruded GFRP profiles for the girder, with the free span suspended by three pairs of seven wire steel strands, and is built to European structural standards.
Dr Gsell will now concentrate on investigating its dynamics to provide detailed understanding of the behaviour of lightweight structures before moving on to other studies.
According to Dr Gsell the next step could include examining the use of tuned mass damper, such as those retrofitted on to the wobbly Millennium Bridge across the river Thames in London, and detecting faults using fibre optic sensors.