Surfaced roads play a crucial role in improving the quality of life for urban communities. This paper will reflect on the changes in the techniques and materials used to surface our urban roads and what the future holds for continuing to use asphalt to meet societies sustainability goals. Civil engineers have always relied on building infrastructure utilising local resources to achieve the most affordable outcome to meet society needs. As society demands have changed, road infrastructure will continue need to evolve as it faces an uncertain future with depleting natural resources and the damaging effects of climate change.
The genesis of building surfaced roads in Sydney goes back to the early 1880’s when hard timber blocks were used to minimise noise and dust. These woodblocks were dipped in tar pitch to and were surfaced with tar binder. With the advent of the motor vehicle in the 1920’s, these blocks were eventually replaced with asphalt and sprayed seals manufactured with bitumen.
As society demands that we become more sustainable, this places new challenges on our engineers to innovate by; reusing existing resources by making the road pavement a linear quarry, reusing repurposed waste to replace non-renewable materials and to keep waste out of landfills, utilise low carbon materials and carbon capture techniques. This paper will explore how we can achieve this by; reusing asphalt and repurposed waste to reduce our demand on non-renewable materials to manufacture asphalt, using biogenetic feedstocks in bitumen to reduce the embodied carbon, utilising renewable fuels and energy to operate our equipment and manufacturing plants.
In conclusion we have almost come full circle from the horse drawn era to the combustion vehicle and now face a new world without carbon fuels which requires circular net zero carbon pavements.