After a general introduction the authors consider the costs of compaction and conclude that constraints are more likely to be physical than economic. Current equipment and practice are mentioned and the principle of the compaction process is discussed. The practical consequences of applying these principles are examined and the planning of the site operations, which requires consideration of the number and characteristics of the rollers employed, the rate at which the material is laid, the laydown temperature and the rate of cooling. The question of the number of roller passes necessary is studied and the authors put forward the opinion that is best to aim at as many as possible. The effectiveness of different types of roller is also analysed. The next part of the paper, concerned with the evaluation of compaction, makes special reference to gamma-ray transmission techniques and discusses the relative merits of "method" and "end product" specifications. The authors conclude that whilst compaction practice relies heavily on experience, it rarely fails to result in poor performance. They believe that improved compaction technology may be required in the future for mixes which make more economical use of materials, but that in the meantime there is a case for using as many rollers as possible with light rollers immediately behind the paver. For the covering abstract of the seminar, see IRRD abstract no 212145. /TRRL/

  • Corporate Authors:

    Asphalt and Coated Macadam Association, Limited

    25 Lower Belgrave Street
    London SW1,   England 
  • Authors:
    • Finey, J T
    • Hills, J F
  • Publication Date: 1974

Media Info

  • Features: Figures; References;
  • Pagination: 25 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00097679
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Conf Paper
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1975 12:00AM