THE USE OF GAP GRADED MIXES IN ASPHALT OVERLAY

A type of gap graded mix intermediate between continuously graded asphalt concrete and a high sand content gap graded rolled asphalt has been used in the Natal asphalt overlay programme with good results. A full scale overlay experiment at Umbumbulu, trial sections at Tugela and a survey of some 150 miles of overlay already completed are described and their performance evaluated. The mix used appears to give good performance in layers thinner than called for in terms of current design methods. Explanations are given for its apparently superior flexibility and crack resistance over the more traditional asphalt concrete. Indirect tensile strength tests have been undertaken, which indicate a high tensile strength for this mix in the temperature ranges experienced in Natal. Economics of stage construction are possible because of the good performance of thin (less than 4") layers of gap graded mix even over old distressed pavements of high deflection levels. /AUTHOR/

• Supplemental Notes:
  • Presented at the Third International Conference on the Structural Design of Asphalt Pavements, Grosvenor House, Park Lane, London, England, Sept. 11-15, 1972.
• Corporate Authors:

  International Conf Struct Design Asph Pvmts (3rd)

  University of Michigan, Department of Civil Engineering
  Ann Arbor, MI  United States  48104

  International Conf Struct Design Asph Pvmts (3rd)

  University of Michigan, Department of Divil Engineering
  Ann Arbor, MI  United States  48104

  Interrational Conf Struct Design Asph Pvmts (3rd)

  University of Michigan, Department of Civil Engineering
  Ann Arbor, MI  United States  48104
• Authors:
  • Knight, K
  • Groth, P
  • Akeroyd, FML
• Conference:
  • Presented at the Third International Conference on the Structural Design of Asphalt Pavements, Grosvenor House, Park Lane, London, England, Sept. 11-15, 1972.
• Publication Date: 1972-9

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 1178-87
• Serial:
  • Volume: 1

Subject/Index Terms

• TRT Terms: Asphalt pavements; Construction management; Design; Economic factors; Mass spectrometers; Performance; Tensile strength
• Uncontrolled Terms: Asphalt grading; Stage construction
• Subject Areas: Construction; Design; Economics; Highways; Materials; Pavements;

Filing Info

• Accession Number: 00261894
• Record Type: Publication
• Report/Paper Numbers: Proceeding
• Files: TRIS
• Created Date: Oct 22 1974 12:00AM