EXPERIMENTAL SPREADING OF PRECOATED CHIPPINGS ON LIMESTONE BITUMINOUS MIXTURES

EXPERIMENTATION DE CLOUTAGE D'ENROBES CALCAIRES

The mountainous regions of the Haut-Doubs and the Jura have very severe winters. They are lacking in volcanic materials but have large deposits of limestone aggregates, the major drawback of which is their susceptibility to polishing. The use of these local materials makes possible the production of low-cost bituminous mixtures; unfortunately the latter become rapidly slippery under traffic and especially in wet weather. A remedial measure consists in covering these mixtures with a surface dressing, but winter conditions make their time-related behaviour very unsatisfactory. The authors outline a method of spreading precoated hard porphyry aggregates on top of limestone bituminous mixtures susceptible to polishing. This treatment, after several years of traffic, results in a differential wear of the limestone mortar, causing the spread aggregates to stand out. This macroroughness leads to: surfacings with excellent drainage properties, a coefficient of longitudinal friction particularly satisfactory at high speeds, and a reduction of skidding under mild black ice conditions. (TRRL)

  • Corporate Authors:

    Laboratoire Central des Ponts et Chausees (LCPC)

    Boulevard Lefebvre 58
    Paris Cedex 15,   France  F-75732
  • Authors:
    • Ballie, M
    • Barberet, M
  • Publication Date: 1978-1-2

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00309462
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 26 1980 12:00AM