Measuring Effects of Warm-Mix Additives: Use of Newly Developed Asphalt Binder Lubricity Test for the Dynamic Shear Rheometer

An emphasis on environmental stewardship has prompted the use of warm-mix technologies aimed at allowing for production of conventional asphalt mixtures at reduced temperatures. Successful use of warm-mix asphalt (WMA) in field demonstrations has created a need for development of mix design procedures. A major impediment in development of these procedures is the evaluation of the effect of WMA technologies on asphalt binder and mixture workability. The objective of this study was to introduce a new test methodology for estimating asphalt binder workability by measuring the lubricity effects of a surfactant-based additive as well as binder foaming processes through novel use of the dynamic shear rheometer with a new testing fixture. The new test allows measuring the coefficient of friction of binders at various temperatures, loading rates, and normal force. Asphalt binder lubricity measurements were correlated to mixture workability tests defined by the compactive effort required to densify a mixture to 8% air voids. Mixture testing was conducted at temperatures ranging from 90°C to 135°C. Results of asphalt binder workability testing demonstrated a significant reduction in coefficient of friction due to the use of a surfactant-based WMA additive and identified a need for revised procedures for evaluation of foamed asphalts. Both warm-mix processes demonstrated enhanced mixture workability relative to the hot-mix asphalt; however, significant differences were not realized until compaction temperatures were below those normally used in production.

• Record URL:
  https://doi.org/10.3141/2180-10
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=Measuring+Effects+of+Warm-Mix+Additives%3a+Use+of+Newly+Developed+Asphalt+Binder+Lubricity+Test+for+the+Dynamic+Shear+Rheometer&author=A.+Hanz&author=A.+Faheem&author=E.+Mahmoud&author=H.+Bahia&publication_year=2010
• Availability:
  • Find a library where document is available. Order URL: http://www.trb.org/Main/Blurbs/Bituminous_Materials_and_Mixtures_2010_Volume_2_164857.aspx
• Authors:
  • Hanz, Andrew J
  • Faheem, Ahmed
  • Mahmoud, Enad
  • Bahia, Hussain U
• Publication Date: 2010

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Photos; References; Tables;
• Pagination: pp 85-92
• Monograph Title: Bituminous Materials and Mixtures 2010, Volume 2
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 2180
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Asphalt additives; Asphalt mixtures; Bituminous binders; Coefficient of friction; Foamed asphalt; Mix design; Rheometers; Surface active agents; Temperature; Test procedures; Warm mix paving mixtures; Workability
• Uncontrolled Terms: Lubricity
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01328168
• Record Type: Publication
• ISBN: 9780309160506
• Report/Paper Numbers: 10-3936
• Files: TRIS, TRB, ATRI
• Created Date: Jan 21 2011 2:44PM