CRITICAL EVALUATION OF ASPHALT MODIFICATION USING STRATEGIC HIGHWAY RESEARCH PROGRAM CONCEPTS

With the introduction of the Strategic Highway Research Program (SHRP) binder tests an evaluation of how different additives affect the critical properties of binders was conducted. Testing done as a part of several projects involved asphalt binders modified with three different types of additives: crumb rubber, polymeric additives, and mineral fillers. The testing included rheological and failure characterization at a number of different temperatures. The temperatures were selected to cover those in the climatic regions encountered in the United States and Canada. The measurements included high- and intermediate-temperature measurements with the dynamic shear rheometer at several temperatures, low-temperature creep with the bending beam rheometer, and low-temperature failure strains by the direct tension test. The need for asphalt modification is discussed. A summary of the results of the testing program is presented. The present work includes information on how these modifiers affect the rheological and failure properties at ranges of temperatures and loading frequencies that simulate application conditions. The changes in the performance-related parameters used in the SHRP specifications as a result of these modifications are also discussed. The results indicate that the proposed specification parameters are sensitive to the effects of the modifiers and that different additives can be used to alter the performance-related properties of asphalts. The results also indicate that major improvements in properties can be achieved with certain modifiers and that these improvements in properties are generally achieved at relatively high temperatures.

Language

  • English

Media Info

  • Features: Figures; References;
  • Pagination: p. 82-88
  • Monograph Title: Unmodified and modified asphalt binders
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714796
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Nov 29 1995 12:00AM