Comparative Evaluation of 4-Inch and 6-Inch Diameter Specimens for Testing Large Stone Asphalt Mixes

Details

• Creators:
  Kandhal, Prithvi S. ; Brown, E.R.
• Subject/TRT Terms:
  • Asphalt mixtures
  • Binder content
  • Aggregates, rock and stone
  • Test procedures
  • Gyratory Testing Machines (GTM)
  • Marshall mix design method
• DOI:
  https://doi.org/10.21949/1404492
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  National Center for Asphalt Technology (U.S.)
• Abstract:
  Increased incidence of premature rutting of heavy duty asphalt pavements has ; been experienced in recent years. There is a general agreement among most ; asphalt paving technologists that the use of large size stone in the binder and ; base courses will minimize or eliminate the rutting of heavy duty-pavements. ; However, the wide acceptance of the Marshall and Hveem mix design procedures ; inhibits the use of large stone mixes because these methods use standard 4-inch ; (101.6 mm) diameter specimens and limit the maximum aggregate size to one inch ; (25.4 mm). ; Modified Marshall equipment and Gyratory Testing Machine (GTM) are now available ; for compacting and testing 6-inch (152.4 mm) diameter specimens to accommodate ; aggregate up to 2-inch (50.8 mm) maximum size. However, some agencies continue ; to use 4-inch diameter specimens for mixes containing 1&1/2inch (38.1 mm) ; maximum size aggregate. This study compares the mix properties such as Marshall ; stability and flow, indirect tensile strength, and permanent deformation (from ; static creep test) obtained on 4-inch and 6-inch (101.6 and 152.4 mm) diameter ; specimens. Both Modified Marshall and GTM equipment were used to compact the ; specimens of these two sizes. The maximum aggregate size ranged from 1/2 to ; l&1/2-inches (12.5 to 38.1 mm). ; The test data indicates increased coefficient of variation when testing 4-inch ; (101.6 mm) specimens of the mix containing aggregate larger than one inch ; (25.4 mm) compared to 6-inch (152.4 mm) specimens. The 6-inch (152.4 mm) ; diameter specimens also had lower variability in creep test compared to 4-inch ; (101.6 mm) specimens. Laboratory and rationally derived data indicating the ; ratios by which stability and flow values increased is also given in the paper. ; It has been recommended to use 6-inch (152.4 mm) diameter specimens for large ; stone asphalt mixes.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/13187/dot_13187_DS1.pdf
• File Type:
  [PDF - 136.25 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:7477d6cdc6162ee7c1b182f3664ca62fb95615f8e7b061c83596161bb4250ee9f71351c99db8fe969c6a9a4fff432c37099a8cceb231a0dfab7b22ad42687fa0