Foamed-asphalt paving mixtures are evaluated under a variety of testing procedures for design of field projects in different areas of the United States and in other countries. Laboratory results and correlations with field experience obtained in one area are often difficult to apply elsewhere. A standard design test procedure for foamed-asphalt mixtures would resolve many problems. Under road conditions, foamed-asphalt mixtures are similar in some ways to emulsion and cutback mixtures, for which desigh test procedures are available. As far as possible, use of established methods provided a logical approach to development of a design test method for foamed mixtures. Test routines for emulsion mixtures that simulate mix compaction during laydown and subsequent curing of the pavement, along with established criteria for test results, have proved equally applicable to foamed mixtures and their use is proposed. They would be preceded by new routines unique to foamed asphalt for the preparation of design test batches ready to be compacted into test specimens. Instructions are provided for tentative appraisals of aggregates and for defining the desired aggregate moisture level, operating conditions for the foamed-asphalt system, and asphalt contents of trial mixes. Acceptance of published emulsion mix design procedures has been hampered by the time required for specimen curing. A novel scheme applicable to both foamed and emulsion mixes is proposed that would provide specimens at three levels of curing yet require less laboratory test time and fewer molds. However, the criteria used to judge the test results may require some adjustment. A method is proposed for predicting the progress of pavement curing through correlation of pavement moisture level with test data obtained in the laboratory on specimens at different levels of curing. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 88-95
  • Monograph Title: Asphalt materials, mixtures, construction, moisture effects and sulfur
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00390796
  • Record Type: Publication
  • ISBN: 0309035546
  • Files: TRIS, TRB
  • Created Date: Dec 30 1984 12:00AM