CONTROL OF AGGREGATE GRADATION FOR ASPHALTIC CONCRETE ---PRE CONFERENCE PROCEEDINGS 3RD IRF MIDDLE EAST REGIONAL MEETING. TOWARDS BETTER ROAD PERFORMANCE, RIYADH, SAUDI ARABIA, 13-18 FEBRUARY 1988. 6 VOLUMES.

The report describes a method for minimizing the failure of asphaltic concrete by permanent deformation (rutting) and also by lack of durability. The method was developed from practical considerations of theory and observations of pavement failures. Rutting of asphaltic concrete is a shear failure and it is resisted principally by the properties of the aggregate in the form of its internal friction. It is generally agreed that an aggregate gradation yielding a maximum density will result in a high value of internal friction; however, this corresponds to a minimum volume of voids, and this is not a desirable characteristic as the limited amount of void space restricts the amount of asphalt to be used and leads to low durability; additionally, a slight increase in asphalt content from the optimum may cause a drastic reduction in shear strength. The method is used to calculate the potential and final void space of an aggregate blend in consideration of its gradation. Assuming limits on the potential void space, air space of the compacted mixture, and asphalt film thickness, an optimum asphalt content is selected for initiating further mixture testing in the laboratory. Examples of the procedure are presented as well as its use in analyzing pavement performance. For the covering abstract of the proceedings see IRRD 817883.

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  • Accession Number: 00486944
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1989 12:00AM