Highly Recycled Asphalt Pavement (HighRAP)


Stockpiles of Reclaimed Asphalt Pavement keep accumulating in Switzerland. The reasons for this include lack of long-term performance experience, as well as the unreliable nature of high RAP mixture design and quality control procedures.


The HighRAP project will address these problems by building on the existing world-wide knowledge of RAP re-use in asphalt layers in order to rapidly implement procedures that would allow confident use of highly recycled pavements in Switzerland. To achieve this, six interconnected studies will be performed as outlined in the figure below. These will include:


  1. Evaluation of RAP processing procedures to improve the recyclability of RAP
  2. RAP characterization methodology,
  3. Mixture aging to determine adequate aging protocol before performance testing,
  4. Refining of balanced mixture design procedures
  5. Use accelerated traffic loading to evaluate longevity of asphalt highly recycled asphalt mixtures
  6. Evaluation of existing and constructing of new test sections with high RAP content




As a result of the research, RAP use requirements will be developed for use by road owners and guidelines for achieving the required performance of high RAP mixtures will be presented to the road construction industry.


Project Period

July 2019 - June 2022