This paper describes the development of an impact testing device for evaluation of pavement base courses. It consists essentially of a laboratory compaction hammer to which has been attached an accelerometer. The peak output from the accelerometer as generated by impact with the ground surface is indicated on a specially designed hand-held meter. The procedure is to apply a series of impacts at the one position until a constant value is being recorded. This usually requires about six blows. Laboratory and field experimental results are presented for a well-graded fine crushed rock, a laterite gravel, a calcareous sandstone and fine sand. These data indicate the influence of moisture content on the impact value. It is deduced that there is a relationship between the Texas Class Numbers and the accelerations, and that a unique value is indicated for the 'dry leg' of the compaction curve; on this basis it is suggested that it should be possible to devise a procedure for acceptance based on the accelerations. Using a 500 gram hammer it is possible to extend the procedure for application to density control of fine sand. It is concluded that the instrument meets the main requirements for an in situ test and that it may provide a means of quickly and economically assessing acceptable construction.

Media Info

  • Features: Figures; References;
  • Pagination: p. 1-6
  • Serial:
    • Volume: 8
    • Issue Number: 8

Subject/Index Terms

Filing Info

  • Accession Number: 00149473
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 13 1977 12:00AM