Bridges

Sustainability is now a critical requirement for infrastructure as well as for buildings and the general built environment as we strive to limit Climate Change. Net Zero by 2050 is Australia's Government objective and this is an important focus in future projects.

Steel bridges may not be what Australian Transport Authorities think of as having a sustainable advantage. In fact, some Authorities actually exclude steel alternatives for road and railway bridges in project specifications, mainly because of expected cost and impact of future painting maintenance. The legacy of past design and construction practices which led to expensive maintenance but which are now outdated seems to be a questionable barrier for modern steel bridges.

This paper presents a strong case demonstrating that steel bridges have a sustainability advantage in many situations, especially where the material properties of steel will serve to achieve safe and economical structures such as pier-redundant bridges, long-span bridges and beautiful, inspiring signature bridges.

The paper will also discuss the specifications for economical, yet superior surface coatings with a low environmental impact as well as enabling fast, safe construction and low future maintenance. New developments in composite steel bridge design, weathering steel solutions and life-cycle costing research and modelling will also be discussed.

Examples of steel structures which have stood the test of time, demonstrating longevity and sustainability will be presented as well as structures which have failed or become unsustainable due to outdated design and construction practices.

In conclusion, the choice of an appropriate steel bridge system, good design and specifications can provide a competitive, sustainable structure, sometimes with unmatched safety at particular sites and projects.