Reuse of thermally purified tar-containing asphalt

Tar contains carcinogenic polycyclic aromatic hydrocarbons (PAH). The Dutch policy is therefore aimed at the complete removal of tar-containing material from the environment, including tar-containing asphalt. Until 2001, tar-containing asphalt could be reused in a cold-bound form in base courses. With the development of techniques to purify tar, its re-use was forbidden by law in 2001. One method of purifying tar is the integration of thermal conversion in an asphalt plant. The binder is destroyed and the recovered energy as well as the hot minerals are used immediately in asphalt production. Although this is a preferred technology, several drawbacks have forestalled its practical implementation and the purification of tar-containing asphalt is now limited to two installations, originally designed for soil cleaning. In these installations the tar contained in the asphalt evaporated or oxidised. The remaining mineral fraction is sold as 'ecogranulate'. Ecoganulate is used as an alternative to primary aggregates and processed demolition waste in base courses. In this application the aggregate is not used to its full potential. Because of its original use, its application as an alternative for primary aggregate in asphalt would be of greater interest. Laboratory testing and, above all, actual projects show its potential in asphalt production. Combined with the high percentage of recycled asphalt granulate this results in a product that may consist of 80% recycled materials, while still being suitable for intensively used Dutch main roads. For the covering abstract of this conference, see ITRD E145817

  • Authors:
    • VAN DE WALL, A R
  • Publication Date: 2006

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01155344
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Apr 23 2010 11:02AM