A range of wearing-course materials suitable for the maintenance of bituminous roads in being compared in a full-scale experiment laid on truck road a1 at Buckden in Cambridgeshire during 1975 and 1976. They include open-textured macadam, pervious macadam, dense bitumen macadam, delugrip materials, rolled asphalt and a surface dressing. Their performance is being assessed from measurements of deformation, deflection, riding quality, texture depth, sideway-force coefficient, braking-force coefficient, permeability, void content, noise and spray and this report gives interim results obtained during the first two years of trafficking. All the wearing-course materials gave good resistance to deformation, good riding quality and, because aggregates of high polished-stone value were used, good resistance to skidding at low speed (50 km/h). The surface dressing, pervious macadam and well-chipped rolled asphalt provided adequate texture depth and showed little reduction in braking-force coefficient for an increase in speed from 50 to 130 km/h whereas the delugrip materials, dense bitumen macadam and open-textured macadam, unable to maintain a substantial texture depth, showed a 20-40 per cent reduction. Some of these low-textured materials proved to be permeable to water. It was also found that they contributed less to the recorded traffic noise and, except for the open-textured macadam, generated more spray than those with deeper texture. (a) (TRRL)

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Authors:
    • Brown, J R
  • Publication Date: 1979

Media Info

  • Features: Figures; Tables;
  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00310086
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Report/Paper Numbers: SR476 Monograph
  • Files: ITRD, TRIS, ATRI
  • Created Date: Jul 22 1980 12:00AM