Recyclability of cold recycled asphalt and bitumen stabilized material

Recycling of asphalt pavements at the end of their service life is a common procedure applied nowadays. Here two main approaches can be distinguished. By cold recycling, for example in bitumen stabilized material (BSM) or cement-bitumen stabilized materials (CBSM), the existing asphalt pavement is milled and mixed with new binders in situ resulting in a new flexible base layer. Ecological advantages of this technology are the preservation of natural resources (aggregates) and the avoidance of hauling of constituent materials as well as reclaimed road materials by in-situ mix preparation, laying and compaction at ambient temperature. The competing technology of hot recycling in asphalt mix plants inhibits the advantage of reactivating the bitumen of the reclaimed asphalt which reduces environmental impact and costs considerably. In the frame of European CoRePaSol-Project the multiple recyclability of cold recycled material and BSM as well as their recyclability in hot-mix asphalt was identified in order to evaluate strategies for the recycling of these materials when they reach their end of service life themselves. Therefore, cold recycled materials were prepared in laboratory, artificially long-term aged and afterwards used in new recycling mixture design for cold recycling mixtures as well as hot-mix asphalt. By comparing the mix designs of BSM after various recycling cycles, the effect of multiple cold recycling is evaluated. By adding the cold-recycled granulate as reclaimed asphalt to hot-mix asphalt, it is evaluated if the bitumen as bound in cold recycling materials can be reactivated in hot-mix processes in future. The recycling effects on hot-mix asphalt were evaluated in terms of crack and rutting resistance. The contribution discusses end-of-life strategies for cold-recycled materials in base layers in the frame of sustainability evaluation of these road materials.

Language

  • English

Media Info

  • Pagination: 8p
  • Monograph Title: 11th Conference on Asphalt Pavements for Southern Africa: CAPSA15, 16-19 August 2015, Sun City, South Africa

Subject/Index Terms

Filing Info

  • Accession Number: 01597068
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Apr 22 2016 11:12AM