Performance Evaluation of Terminal Blend Tire Rubber HMA and WMA Mixtures—Case Studies

Terminal blend tire rubber (TR) with less than 10% rubber was initially introduced in hot mix applications during the mid 1980s in California and Florida. Since then, it has been used in several other states with increasing amounts of rubber up to 20% as a finished PG-TR binder in recent years. A TR modified asphalt binder is made using a finely ground crumb rubber modifier that is typically blended and digested into the binder at the asphalt refinery. The use of TR asphalt binders in dense graded hot mix asphalt (HMA) mixtures in Nevada has been fairly limited. The main concern for the Nevada Department of Transportation (NDOT) was the lack of performance records for TR asphalt mixtures compared to the outstanding performance of the polymer-modified asphalt mixtures typically used in Nevada. This paper summarizes the efforts conducted in Nevada to evaluate and implement the use of TR binders in dense graded asphalt mixtures. An extensive performance evaluation was undertaken in the laboratory to assess and compare the TR binders to the standard polymer-modified asphalt binders used in Nevada. Subsequently, based on the findings, pilot demonstration projects were constructed in 2008 in Nevada and California with side by side sections of TR and polymer-modified asphalt mixtures. Visual inspections conducted in 2011 of both projects revealed no visual distresses, with the pavement condition being excellent and uniformly the same along the total length of both test sections. Giving this promising field performance of TR mixes, a study was initiated in 2010 to evaluate the use of TR in warm mix asphalt (WMA) mixes. The results for two types of warm mix additives are presented in this paper, Advera® and Sasobit®. Mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles. The study specifically examined the potential effect of aggregate residual moisture in the mixture as a result of insufficient aggregate drying during its production.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/02702932
• Authors:
  • Hajj, Elie Y
  • Sebaaly, Peter E
  • Hitti, Edgard
  • Borroel, Corina
• Conference:
  • Asphalt Paving Technology 2011
  • Location: Tampa FL
  • Date: 2011-3-27 to 2011-3-30
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 665-696
• Serial:
  • Journal of the Association of Asphalt Paving Technologists
  • Volume: 80
  • Publisher: Association of Asphalt Paving Technologists (AAPT)
  • ISSN: 0270-2932
  • Serial URL: https://www.asphalttechnology.org/site_page.cfm?pk_association_webpage_menu=9169&pk_association_webpage=19109

Subject/Index Terms

• TRT Terms: Asphalt rubber; Hot mix asphalt; Performance measurement; Rubber; Tires; Warm mix paving mixtures
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01367552
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 10 2012 3:17PM