DEVELOPMENT AND USE OF GEORGIA LOADED WHEEL TESTER

The Georgia Department of Transportation began development of a loaded wheel tester (LWT) in 1985 to better evaluate the rutting susceptibility of asphaltic concrete mixes. It has been believed throughout the industry for some time that Marshall stability tests are inadequate to accurately predict rutting potential of various mixes. With the Georgia LWT, the susceptibility of a mixture to rutting can be determined in the laboratory during the design stage, and modifications to the design can be made at that time if needed. The machine can be adjusted for various weight, air pressure, and temperature conditions to simulate and test for performance under the actual field environment. The machine has been made to be a completely portable, self-contained unit with its own environmental heating chamber. Several research projects have been conducted with the Georgia LWT in order to evaluate the effect on performance of aggregate gradation, tire pressure, vehicle loading, and pavement temperature. Testing has been done on specialized mixes such as stone matrix asphalt, which shows that these mixtures are more resistant to rutting than conventional mixes even though Marshall stability test values may be lower. Asphalt mixtures produced under the Strategic Highway Research Program Level I and II volumetric design methods may still be prone to rutting. The Georgia LWT is an economical tool that can be used as a "proof tester" for properly evaluating the rutting resistance of these mixtures before they are placed on the roadway.

Language

  • English

Media Info

  • Features: References; Tables;
  • Pagination: p. 202-207
  • Monograph Title: Hot-mix asphalt design, testing, evaluation, and performance
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714848
  • Record Type: Publication
  • ISBN: 309061563
  • Files: TRIS, TRB
  • Created Date: Dec 4 1995 12:00AM