Bridges

There is a growing requirement for infrastructure to consider sustainable practices to ensure the preservation of resources and achievement of climate change ambitions. In the areas of recycled materials, the Australian Federal Government has implemented a progressive ban on the export of recycled materials, and in Victoria, the State Government announced the Recycled First policy in March 2020 to encourage the development of a circular economy in government funded infrastructure. However, much of the focus of recycled materials in road and rail infrastructure is largely associated with fill material and asphalt, with reasonably limited use of recycled materials for bridge related elements. This paper explores current and emerging recycled material technology to determine if itís possible in the near future to construct a bridge entirely from recycled materials.

Current recycled materials that can be used in bridge construction include (i) blast furnace slag, fly ash, and recycled glass as various additives or replacement materials in concrete, (ii) recycled plastic for noise walls, fascia panels, drainage pipes and conduits, (iii) recycled steel for reinforcement bars, and (iv) crumbed rubber, plastics and glass as additives to asphalt.

Emerging technologies that utilise recycled materials that are likely to result in new bridge construction practices include (i) further replacement of concrete with recycled materials, (ii) construction of key structural elements entirely from recycled plastics (include bridge decks), and (iii) the potential for use of recycled materials in ancillary bridge elements such as barriers, architectural façades, road signage and line marking.

While there is still additional research, trials and funding required to prove the suitability of recycled materials to be used in bridge construction, it will not be long until the use of recycled materials becomes more common place, and the potential for an entirely recycled bridge becomes a reality.