Australia has approximately 10 000 timber bridges, most of which were constructed before the year 1940. When these bridges were designed, they were designed with lower traffic loads in mind. In addition to this fact these girders are now severely degraded due to dry rot and termite attack. The maintenance of these bridges is crucial to the public as they form vital transport links, particularly in rural areas.
At the moment funds given to bridge maintenance are totally inadequate, not to mention shortages in budget allocations for upgrading the bridges to concrete or steel. On the political front, the prospects for increasing this funding are extremely unlikely. Therefore, a new, cheaper method of rehabilitation needs to be developed.
In response to these issues, this paper suggests a method of rehabilitating timber girders in-situ, using pultruded Glass Fibre Reinforced Polymer sections. This paper is written as a ‘proof of concept’ for this proposal.
The findings of this paper indicate that savings of around 70% are possible while restoring the girders to their original strength. For this reason, it is recommended that this proposal be investigated further because the future benefits, political and economic, may be huge.