Effect of Foamed Binder Characteristics on Warm Mix Asphalt (WMA) Performance

Warm Mix Asphalt (WMA) has been introduced to produce and place asphalt pavements at lower temperatures as compared to conventional Hot Mix Asphalt (HMA). While the WMA technologies are appealing, their long-term performance relative to HMA is not well-known. Among various WMA technologies, foam-based methods are the most widespread WMA applications. However, most of the current WMA design is based on empirical data and there is limited understanding of the fundamental behavior of the foamed binders and mixtures. Therefore, there is a growing need for understanding the WMA pavements from binder production to mixture performance. In this study, the relationship between the foamed binder characteristics and the mixture performance was investigated. Using a nozzle-based laboratory foamer, five different binders were foamed at different water contents and air pressure levels. Potential binder quality indicators such as the Expansion Ratio, Half-Life, and Bubble Size Distribution were measured using a novel testing device called Asphalt Foam Collapse Test (AFCT). Then, mixtures were prepared with these binders and their performances were compared in terms of their compactability, permanent deformation (rutting), fatigue cracking and moisture susceptibility. These properties were investigated using Dynamic Modulus, Flow Number, Push-Pull, and Tensile Strength Ratio tests. It is concluded that the characteristics (i.e., quality) of foamed binder significantly affects the overall WMA pavement performance. It is recommended that WMA specifications should consider the characteristics of foamed binders in order to improve the performance of foam-based WMA pavements.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK20 Characteristics of Asphalt Materials. Alternate title: Effect of Foamed Binder Characteristics on Warm-Mix Asphalt Performance.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Ozturk, Hande I
  • Kutay, M Emin
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: 15p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Air pressure; Bituminous binders; Compactibility; Fatigue cracking; Foamed asphalt; Moisture content; Pavement performance; Rutting; Warm mix paving mixtures
• Uncontrolled Terms: Moisture susceptibility
• Subject Areas: Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01518319
• Record Type: Publication
• Report/Paper Numbers: 14-3953
• Files: TRIS, TRB, ATRI
• Created Date: Mar 17 2014 4:18PM