EVALUATION OF LABORATORY METHODS SIMULATING AGING EFFECTS OF ASPHALT BINDER

The effects of short-term and long-term aging are important when evaluating the properties of asphalt binder. Thus, the properties of asphalts aged for the short term and the long term are considered in the Superpave binder specification. The most practical way of predicting the effects of aging within an asphalt binder is through laboratory simulation methods. For many years the thin film oven test (TFOT) method and the rolling thin film oven test (RTFOT) method have been used to simulate short-term aging. To simulate long-term aging the pressure aging vessel (PAV) method was developed within the Strategic Highway Research Program. However, the Superpave binder specification uses only the RTFOT method for short-term aging and uses RTFOT along with the PAV method for long-term aging. For a short period of time AASHTO considered the use of either the TFOT method or the RTFOT method and then the PAV long-term aging procedure for short-term aging. Unfortunately, few published data address this issue. The test data from a testing program conducted to evaluate these laboratory procedures for short-term and long-term aging with different asphalt binders are presented. The effects of aging are evaluated by dynamic shear stiffness, measured by using the dynamic shear rheometer at three intermediate temperatures. The data indicate that there are no significant differences at the 95% confidence interval between the properties of RTFOT-aged residues and those of TFOT-aged residues after exposure to the PAV procedure. The differences before aging by the PAV procedure, however, still exist. It is recommended that only one short-term aging procedure be used for the Superpave binder specification and that work be conducted to develop or improve the short-term aging procedure.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 13-20
  • Monograph Title: Unmodified and modified asphalt binders
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714789
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Nov 29 1995 12:00AM