Asphalt Sustainability and Innovation
Sustainable and Circular
As a pavement construction material, Asphalt more than any other satisfies principles of Sustainability and Circular Economy in line with EU policy objectives set out in the European Green Deal (Dec ‘19) and the Circular Economy Action Plan (March ‘20) which prioritise Prevention and Re-use over Recycling.
Whichever way you look at the Waste Hierarchy Pyramid, the fact that asphalt is 100% reusable puts it at a higher level in the pyramid than recycling, based on the definitions below. These definitions are derived from broad definitions of Reuse and Recycling in the Waste Framework Directive.
Asphalt Reuse
Operation by which Reclaimed Asphalt (RA) is added to new asphalt mixes, with the aggregates and the bituminous binder performing the same function as in their original application.
Asphalt Recycling
Operation by which reclaimed asphalt (RA) is used as unbound sub-base, foundation, fill or road material, with the recovered aggregate and bitumen performing a lesser (or alternative engineering) function than in the original application.
Use of Recovered Asphalt Pavement (RAP) in Ireland
Asphalt is 100% reusable in that both components, the aggregate, and the binder, are fully reusable to perform their original function, thus satisfying the definition set out above. In addition, the reuse operation can be repeated many times ensuring the long term circularity of the process.
Recycling of asphalt as aggregate only (black stone) does not capture the environmental or economic value of the bitumen component, which is consequentially lost forever. The bitumen in the Recovered Asphalt Pavement (RAP) is re-activated by heat in hot mix plants; the maximum re-activation of the bitumen properties cannot be achieved in cold processes.
IAPA’s position on the treatment of RAP in Ireland is set out in this Position Statement
IAPA members are already investing heavily in reuse facilities in their plants and are committed to continue doing so with the help of regulations that will ensure that the first option is to fully reuse all RAP arisings in new asphalt products, before any alternatives are considered.
Asphalt Plants with reuse facilities in place are identified on our Plant Locator Map with green pins.
The introduction of Environmental Product Declarations (EPD) highlights the importance of proper reuse of reclaimed asphalt where the carbon savings in replacing virgin aggregate and binder are fully captured, especially from the bitumen component which could be lost in alternative recycling processes.
For more on RAP reuse go to: Asphalt and Circular Economy - EAPA
Innovation
More innovation in asphalt production and paving has occurred in the past 20 years than in many previous decades and the pace continues to accelerate. IAPA members regularly engage with Transport Infrastructure Ireland (TII) on innovative trials on areas such as:
- Higher levels of RAP in new mixes
- Warm Mix technology
- Warm Mix incorporating RAP
- Hot Mix with Lime
- Non Destructive Testing
Products
A much wider range of products is now available to clients with the introduction of Stone Mastic Asphalt, Thin Layer Asphalt and Porous Asphalt. TII’s Irish Analytical Pavement Design Method (IAPDM) encourages innovation in mix design by taking enhanced performance characteristics of materials into account at the design stage. The introduction of Environmental Product Declaration (EPD) requirements will also continue to drive innovation in product development.
Manufacturing
Asphalts plants continue to benefit from innovations in burner design, fuel types and efficiencies, control and monitoring systems, and general noise and emissions reducing technologies. A major innovation in manufacturing is the introduction of Warm Mix Asphalt (WMA) technology. Various additives and techniques are employed to reduce mixing temperatures by 20 to 40 degC with resultant lowering of emissions, fuel savings and improved operative comfort, while still meeting all performance requirements of the material.
Paving
The advances in paving equipment technology continues to improve the quality and safety of paving operations. Supply trucks, pavers and rollers can be fitted with measuring and monitoring devices to provide improved records of compaction, texture measurements, 3m RSE, IRI etc. These systems help to improve safety by reducing interaction between operatives and machines and require less technical monitoring staff on site. Trials also demonstrated a high level of comfort and enthusiasm using the new technology amongst all staff involved.
For more on Asphalt Innovation go to https://eapa.org/innovation-2/