Full-scale research on the compaction of gravel-asphalt mixtures was conducted to study the influence of the following parameters: vibratory equipment, number of passes, nature of the gravel-asphalt mixture, temperature of compaction, thickness compacted, 1/4 frequency and eccentric moment of the eccentric shaft, on the quality of compaction in terms of mean density through the entire thickness and in terms of the densities of elmentary layers about 4 cms thick at the top and bottom of the compacted course. The equipment employed was representative of the ranges of vibrators for the compaction of pavement courses currently available on the French market and belonging to three broad categories: self-propelled single-wheeled rollers, combination pneumatic-tyred vibratory rollers and tandem rollers. Compaction was performed mainly on gravel-asphalt mixtures not very easy to work (completely crushed aggretate). This research revealed the following main points: (1) The economically worth-while number of passes may vary greatly. (2) The choice of equipment is very important. (3) For a given degree of compaction to be obtained, the yield of a vibratory roller can vary enormously (ten-fold, for example) depending on the material compacted. (4) There is no unique relationship between density at the bottom of the course and average density. These two criteria must be considered simultaneously. (5) For a given vibratory roller, the use of the largest eccentric and of the maximum corresponding frequency seems to produce better compaction when the thickness is about 15 cms. (6) Under the commonest working site conditions, the optimum speed is about 3 km/hr. (7) The on-site behaviour of gravel-asphalt mixtures under compaction is difficult to predict. (8) Under certain special on-site conditions (small thickness, heavy machine) there appears to be a maximum number of passes beyond which the gravel-asphalt course breaks up, especially in its upper part.

  • Corporate Authors:

    Central Laboratory of Bridges & Highways, France

    75732 Paris,   France 
  • Authors:
    • MacHet, J M
    • Morel, G
    • Valeux, J C
  • Publication Date: 1976-12

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 83 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00163616
  • Record Type: Publication
  • Report/Paper Numbers: Resh. Rpt. LPC No 63
  • Files: TRIS
  • Created Date: Oct 29 1977 12:00AM