Recycled asphalt

Groups: 
  • Design-Build Contracts
Category: 
  • Materials

Basic

Requirements and Criteria Type: 
  • Technical Specification (Requirement Specifications)

Main Objective: 

For current road projects, materials account for approximately two thirds of emissions. In order to reduce emissions from the production of asphalt and energy consumption, as well as reducing the use of resources, more recycled asphalt should be utilised in the production of new asphalt. Recycled asphalt can be produced at asphalt plants with recycling ratios of 80 – 100%. Currently, an average of 6.4% recycled asphalt is used in the production of new asphalt. This share should be at least 10%

Requirement Specification: 

Recycled asphalt produced using suitable mixing plant equipment in a way in which the mixing results in a homogeneous material should be used. The requirements concerning the material type have been met using the proportion of asphalt granules used for standardised material types as described in the Norwegian Public Roads Administration’s manual N200. This also applies to the mechanical strength of the stone materials.

For high recycling ratios, the binder stiffness must be adjusted in accordance with NS-EN13108.

The quantity and type of additive must be documented digitally in the technical datasheet for the asphalt and submitted to the client prior to the initial asphalt delivery.

Contractors may deviate from the CO2 intensity if they are able to demonstrate that the overall solution works out better than by selecting products based on these requirements.

Documentation of the Requirement Specification: 

Digital technical datasheets must include information about:

- amount of admixed recycled asphalt (%)

- designation of the recycled asphalt in question

- traceability for the declaration of recycled asphalt

- bitumen softening point in the recycled asphalt (in case of hot asphalt materials)

- viscosity at 60° for the bitumen in recycled asphalt (in case of semi-hot asphalt materials)

Technical datasheets from the producers must be available in a digitally structured format adapted for open BIM.  

Information about the Requirement Specification: 

Asphalt consists of 95 per cent stone and 5 per cent bitumen. The volume of recycled asphalt in Norway is around 15% of the volume of asphalt produced. Recycled asphalt varies in terms of geographical distribution, supply is high in central areas, where high recycling ratios can be used in asphalt production. It is important to enter into dialogue with the market before you plan to use this requirement, to check whether they are able to supply recycled asphalt and how much.

The quality of asphalt containing recycled asphalt is just as good at a high ratio of recycled asphalt or when using recycled materials. In order to ensure adequate asphalt quality (applies to all types of asphalt), it is important to ensure proper execution, favourable weather conditions during spreading, good adhesive quality, correct material temperature, etc. It is therefore a good idea to consider the season when it comes to asphalt planning and to consider measures such as substrate heating.

The use of recycled asphalt is one of the contributing factors in achieving the goal of a 40-50 per cent CO2 reduction from the development, operation and maintenance of infrastructure in the national transport plan. CO2 emissions are reduced by 6% for every 10% of recycled asphalt used in new asphalt.

The owner (client, road owner) is responsible for ensuring that recycled asphalt is processed in a lawful manner, whether it is moved to temporary storage for reuse, which is normal for all types of pure recycled asphalt, or landfilled if necessary.

Criteria Relations and Conflicts: 

Low-temperature asphalt

Relatert kriterium

This requirement may be used in conjunction with the contractual condition concerning low-temperature asphalt.

Related links: 

Published: 24. Nov 2020, Last modified: 28. Dec 2020