Bitumen is a unique substance that starts as crude oil, is refined, and then combined with aggregate to make asphalt and sprayed seal road surfaces. These surfaces provide safe, quiet, and long-lasting pavement that connect people, goods, and services right across Australia.
Without these durable surfaces, society would be vastly different, but most people take asphalt pavements for granted. Those of us who work in the pavement industry know the significance of asphalt pavements, and I encourage each of you to be proud of the work we do. I also encourage you all to promote the importance of what we do to others around us.
Even more importantly, we should ensure that all stakeholders in our industry are aware of the environmental advantages of asphalt over other paving materials.
Process Can Be Repeated
Firstly, asphalt paving is 100-percent recyclable and can be recycled over and over again.
A deep lift asphalt pavement or perpetual pavement that is over 20 years of age may have suffered some surface damage, but generally this damage is only “skin deep.” The minor surface damage in a wearing course can be milled off and quickly replaced with a new wearing course, with minimal interruption to traffic flows and at low cost.
Asphalt removed from a road pavement remains asphalt, a valuable combination of bitumen and high-quality aggregates. This material is referred to as reclaimed asphalt pavement or RAP. RAP can be readily returned to an asphalt plant where it can be combined with virgin materials and applied to another road or pavement project. In another 20-plus years, the same process can be repeated.
Asphalt is not consumed, but remains asphalt indefinitely. This is unlike other materials, such as concrete, that can be used for pavement surfaces once, and then if it is recycled, can only be used for lower value purposes, such as fill or road base.
Asphalt surfaces are therefore 100-percent recyclable and save significant amounts of new materials.
Reduces Greenhouse Gas Emissions
Using RAP not only reduces the demand for new materials, it also greatly reduces greenhouse gas emissions. The manufacture of bitumen is a low source of greenhouse emissions, but some energy is used in its manufacture and in the extraction, crushing, and transport of aggregates. The use of RAP reduces the greenhouse emissions by removing the need to make and supply new materials. The use of RAP in asphalt readily reduces greenhouse emissions by at least 10 to 20 percent. RAP also has great synergies with warm-mix asphalt providing even more environmental benefits, as well as performance benefits.
Those of us working in our industry can be proud of the part we play in society, not only as we build quality roads and pavements, but also because we are a green industry. An industry that produces low greenhouse emissions compared to other road surfaces and an industry that can recycle asphalt over and over again.
Benefits Are Clear
The benefits of asphalt as an environmentally friendly product are clear, and we should help to educate communities and all stakeholders that asphalt is more than sticky black stuff, letting them know that, as asphalt is 100-percent recyclable, it is one of the greenest construction materials available on the market today.
As an industry that takes its impact on the environment very seriously, we should continue to encourage the use and development of green pavements through practices such as the increased use of RAP and low-energy technologies such as warm mix.BACK TO ISSUE