CONSTRUCTION OF BITUMINOUS BASES AND SURFACINGS FOR LOW COST ROADS

Accumulated knowledge of the construction of road bases relates largely to mechanically stable materials, such as crushed rock. These are sometimes not obtainable, particularly in remote parts of developing countries; because of this, the art of soil stabilisation has developed. In the Middle East aggregates are often scarce but oil products are readily available. The region has therefore provided some of the earliest examples of bituminous stabilisation, which originally provided thin running surfaces over compacted sand. Bituminous stabilisation can also enable local sand to be used for base construction and various test methods and design criteria have been proposed for such work. The overseas unit of the Transport and Road Research Laboratory (UK) has participated in full-scale experimental trials supported by laboratory research, which has enabled acceptance criteria for bitumen-stabilised sand bases suitable for light/medium traffic to be proposed. The paper discusses construction methods for bituminous stabilisation and describes current research at the laboratory. Bituminous surfacings range from surface dressings to hot premixed materials. The paper discusses surface dressing, which is important both as an initial running surface on new bases and as a maintenance treatment. Premixed bituminous materials, both as bases and surfacings, might perhaps be considerd as inadmissible within the scope of low-cost roads. Such roads, however, are invariably found to require progressive improvement because of the traffic growth which accompanies development, itself largely a product of the low-cost road. There is evidence of a growing use of strengthening overlays and principally for this reason the paper briefly discusses premixed materials and their applications. Performance characteristics in temperate countries are well established, but comparatively little is known of the performance of different mix types in hotter environments. The overseas unit is doing some research, including full-scale trials, but further opportunities for such trials are needed. (a). This paper was presented at a conference on low cost roads, Kuwait 25-28 November 1974. /TRRL/

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Authors:
    • HITCH, L S
    • Russel, RBC
  • Publication Date: 1974

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 44 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00131451
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: PA. 88/74 Conf Paper
  • Files: ITRD, TRIS
  • Created Date: May 14 1976 12:00AM