APPLICATION OF MICROWAVE ENERGY FOR INDIRECT DETERMINATION OF ASPHALT TOTAL POLARITY AND SULFUR AND SULFIDE CONTENT

A simple, inexpensive, and rapid - yet accurate - method is presented for the indirect determination of relative total polarity and sulfur and sulfide content of asphalt. For a given asphalt, the three parameters can be calculated from one measurement on a scientific microwave instrument. Using the eight Strategic Highway Research Program core asphalts, the dielectric heating time required for 10-g asphalt to reach a target temperature of 150 deg C was measured: AAD-1 took 10 min, whereas AAM-1 took 111.5 min. Because of this wide time range covered by the eight asphalts, the dielectric heating time may serve as a characterization test. The dielectric heating time correlates perfectly, r-squared = .998 or 1.00, with total polarity of the four core asphalts for which total polarity has previously been determined by others. The curve equation was then used to calculate total polarity of the other four core asphalts, and may be used for any given asphalt once its dielectric heating time to reach a target temperature is measured. For the seven core asphalts with a nickel to vanadium ratio (Ni/V) < 1, the dielectric heating time correlates perfectly (r-squared = 1.00) with the sulfur content previously determined by others. For AAG-1, ABM-1, and ABD-1 (all have Ni/V > 1), a separate equation applies, also with r-squared = 1.00. Sulfide content, previously determined by others, for the seven core asphalts with Ni/V < 1 correlates perfectly (r-squared = 1.00) with dielectric heating time. No separate equation could be derived for asphalts with Ni/V > 1 because only sulfide content of AAG-1 was known. For a given asphalt, sulfur and sulfide content can be calculated from the corresponding equation once the dielectric heating time is measured. The proposed method has a reasonable repeatability and bias for the three determined parameters.

• Record URL:
  https://doi.org/10.3141/1638-01
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=APPLICATION+OF+MICROWAVE+ENERGY+FOR+INDIRECT+DETERMINATION+OF+ASPHALT+TOTAL+POLARITY+AND+SULFUR+AND+SULFIDE+CONTENT&author=S.+Bishara&author=D.+MAHONEY&publication_year=1998
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309065100
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1638, Asphalt Mixture Components.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Bishara, Safwat W
  • MAHONEY, D
• Publication Date: 1998

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 3-11
• Serial:
  • Transportation Research Record
  • Issue Number: 1638
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Asphalt; Dielectric materials; Energy; Equations; Heating (Structures); Microwaves; Nickel alloys; Sulfur; Vanadium
• Uncontrolled Terms: Repeatability; Sulfur content
• Old TRIS Terms: Dielectric heating time; Microwave energy; Nickel/vanadium ratio; Polarity; Sulfide content
• Subject Areas: Energy; Highways; Materials; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00756174
• Record Type: Publication
• ISBN: 0309065100
• Files: TRIS, TRB, ATRI
• Created Date: Nov 12 1998 12:00AM