THE USE OF PROPANE-PRECIPITATED ASPHALT (PPA) IN BITUMINOUS PAVING MIXTURES (WITH DISCUSSION)

For a long time, but especially in the past decade, Propane-Precipitated Asphalt (PPA) has been used around the world as a component of asphalt cement as well as of cutbacks and emulsions at refineries where PPA was surplus. In these refineries, there is a constant striving for establishing the maximum proportions of PPA that can be incorporated in paving asphalt formulations. This paper summarizes the first part of a comprehensive research study on the use of asphalt cement containing PPA as a binder in bituminous paving mixtures. The research involved the testing of about 50 different samples of straight-run asphalt cements and PPA asphalt cement blends containing between 20% and 85% PPA in two- and three-component blendings. The testing programs involved an evaluation of the original rheological and physical properties as well as the long-term, age-hardening aging curves at different levels of temperature. Bituminous mixtures, involving durable and sensitive aggregates and different blendings of PPA asphalt cements, were evaluated by long-term hot-water immersion. Durability curves representing moisture-damage development were formed for immersion periods of up to 14 days. Test results were analyzed, using specific concepts and models developed for asphalt age-hardening and bituminous-mixture durability.

• Corporate Authors:

  Association of Asphalt Paving Technologists (AAPT)

  400 Selby Avenue, Suite I
  St Paul, MN  United States  55102
• Authors:
  • ISHAI, I
  • Tuffour, Y A
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1987

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 599-631
• Serial:
  • Volume: 56

Subject/Index Terms

• TRT Terms: Age hardening; Bituminous mixtures; Durability; Laboratory tests; Loss and damage; Moisture damage; Physical properties; Rheological properties; Water
• Old TRIS Terms: Hot-water immersion; Propane-precipitated asphalt
• Subject Areas: Highways; Materials; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00739811
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 29 1997 12:00AM