RUTTING PROPERTIES OF A DUNE-SAND PAVING MIXTURE (DISCUSSION, CLOSURE)

The results of a laboratory evaluation of a dune-sand for use as a base course in a flexible pavement are presented. The principal part of the study was concerned with the development of an equation for relating permanent deformation (rutting) to the combined effects of (a) number of load applications, (b) temperature, (c) surface pressure, and (d) dynamic modulus of elasticity of the supporting subgrade. The mixture evaluated was a dune-sand from Arizona with asphalt of the AR-4000 grade at an optimum content of 14 percent by weight of sand. Permanent deformation specimens were 18 in. in diameter and the height varied from 2 to 6 in. Variation in subgrade support was obtained with synthetic rubber pads 18 in. in depth and 6 in. in height having estimated moduli of 8,000, 20,000, and 30,000 psi. The constant load system operated at a frequency of 11.5 Hz, and contact areaa was varied to yield pressures of 38.5, 61.6, and 98.0 psi. It was found that the optimum specimen height was 4 in. if failure was assumed to have occurred when the rut was 0.4 in., in depth. For this constant specimen height, an equation relating load repetitions (N) to temperature (T), stress (sigma), and subgrade modulus (ES) is presented. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 11-20
  • Monograph Title: Asphalt materials, mixtures, construction, moisture effects and sulfur
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00390785
  • Record Type: Publication
  • ISBN: 0309035546
  • Files: TRIS, TRB
  • Created Date: Dec 30 1984 12:00AM