Objectives & Outputs

Key objectives of the research are proposals of harmonised test, mix design and pavement design procedures for launching the discussion in CEN committees with following focus:

  • harmonized advanced mix design procedures based on traditional mechanical approach of analysis of performance properties for these types of mixes, applicable to all European countries;
  • premises and possibilities for introducing performance-based mix design for more effective use of cold-recycled bitumen stabilized materials;
  • procedures to estimate material parameters feasible for the application in pavement design methods;
  • determine the (multiple) recyclability of cold-recycled material with respect to the impact on mix design and characterization;
  • suitable tools for verification of environmental stability (leaching, tar detection, asbestos release) and for assessing the eco-balance of cold recycling techniques.




Deliverable Name / Report Name


Report on available test  and mix design procedures for cold-recycled bitumen stabilised materials


Report on harmonised mix design procedure: Drafts for mixing, curing and test methods as well as mix design procedure


Report on durability of cold-recycled mixes: Test procedures for simulating long-term aging, moisture damage, cracking and fatigue


Draft of harmonised test procedures for durability characterization


Report on incorporation of cold-recycled pavement layers in empirical and mechanistic pavement design procedures


Report on activity of RA binder in cold-recycled mixes


Report of recyclability and multiple recyclability of cold-recycled mixes in cold and hot recycling


Report on environmental benefits associated with encapsulating hazardous materials



Expected benefits to National Road Authorities

  1. Broad knowledge on using cold recycling techniques already exists in various countries inEuropeand international. The knowledge transfer indicated large discrepancies for testing, curing and designing cold-recycled materials following different national authorities. Evaluate existing design methods and testing protocols and propose suitable harmonization should lead to better sharing of the existing expertise and best practice.
  2. Mix designs are usually done and evaluated by volumetric and mechanical properties like voids content, compactability and strength characteristics. Performance-based characterization and design are used in very limited extent. This is limiting a more efficient use of cold recycling techniques. The project is giving guidance, defining suitable performance tests and recommending threshold limits.
  3. Multiple recyclability has so far been touched in very limited range. Because there are many road section recycled during last 15-20 years, it is only question of time, when information will be needed confirming the possibility of such reuse. The project will evaluated the possibilities to use once cold-recycled bitumen stabilized material again, by giving technical data and advice to road authorities about the suitable solutions.
  4. Aspects covered by environmental stability address important part of build structures which are usually underestimated or seen as a burden. Nevertheless understanding leaching potential, possibility to immobilize tar or asbestos, giving possibilities to reuse rubber modified asphalt and presenting the carbon footprint of cold recycling will help in developing smart strategies for fast, waste-less, energy efficient road rehabilitation with tenable utilization of road users’ taxes and other types of public charging.