PERFORMANCE-RELATED SPECIFICATION OF HRA WEARING COURSE FOR HEAVILY TRAFFICKED ROADS

Hot rolled asphalt (HRA) wearing courses have been specified for many years using a manufacturing recipe, the asphalt being transported, laid and compacted in a prescribed way, optimum binder content for HRA determined using the Marshall test being the only concession to mixture design. Recent surveys have shown that an HRA wearing course generally performs well, however at sustained high temperatures, such as those experienced in 1995, and in heavy traffic, HRA can be susceptible to permanent deformation. The Highways Agency introduced a draft performance specification, Clause 943 of the Specification for Highway Works. The draft clause was introduced on a contract specific basis. The aim was to reduce deformation by limiting the maximum wheel tracking rate and total rut depth and ensuring long term durability utilizing a maximum air voids content (5.5%) and minimum binder volume 15.5% on laid 35/14 HRA wearing course. The overall success of the draft specification will be determined by long-term performance of the trials. Initial results are presented in this paper. For the covering abstract, see IRRD E100730.

  • Corporate Authors:

    THE INSTITUTE OF ASPHALT TECHNOLOGY

    OFFICE 5, TRIDENT HOUSE, CLARE ROAD
    STANWELL, MIDDLESEX  United Kingdom  TW19 7QU
  • Authors:
    • WHITEOAK, C D
    • Nicholls, J C
  • Publication Date: 1998

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00764425
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: May 28 1999 12:00AM