CONSTRUCTION AND PERFORMANCE OF SAND-ASPHALT BASES

Sand-asphalt base construction practices and field performance are described based on extensive field inspections and interviews with state transportation personnel in Florida, Georgia, Maryland, and South Carolina. The results are also summarized of laboratory fatigue and rutting tests performed on both sand-asphalt and sand-stone asphalt mixes. Laboratory studies indicate that the fatigue characteristics of a sand-asphat mix can be generally controlled by (a) limiting the void content to 12-15 percent, (b) using asphalt contents greater than 5.5-6.5 percent, and (c) designing the mix with a Marshall stability as high as practical. Important variables that affect rutting in a sand-asphalt mix are asphalt content, Marshall stability (or air void content that appears to be related to Marshall stability), and the characteristics for the aggregate. The specific effects of these variables are presented for selected mixes. Sand-asphalt and sand-stone blend asphalt mixes can be successfully used as bases on primary and Interstate highways. Rutting in pavements constructed by using 150- to 200-mm (6- to 8-in.) sand-asphalt bases is typically between 8 and 15 mm (0.3 and 0.6 in.). An allowable rut depth for design purposes of 10 mm (0.4 in.) is recommended for primary and Interstate pavements. The 50-blow Marshall mix design method can be used for sand-asphalt bases, provided rutting and fatigue resistance of the mix is taken into account. The blending of up to 75 percent crushed aggregate with sand offers an excellent way to descrease rutting and increase fatigue life of the mix while still using local sand. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 13-22
  • Monograph Title: Performance of pavements designed with low-cost materials
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00319133
  • Record Type: Publication
  • ISBN: 0309029996
  • Files: TRIS, TRB
  • Created Date: Oct 27 1980 12:00AM