Comparison of Procedures to Predict Moisture Susceptibility Characteristics in Warm Mix Asphalt

Georgia Department of Transportation (GDOT) recently let its first warm mix asphalt (WMA) project in response to the need to evaluate the WMA technology and how it correlates with materials specific to Georgia. While benefits from energy savings and cost are clear from reduced mixture production temperatures, indications of increased susceptibility to moisture damage in these mixtures are of concern to GDOT. Also, no single procedure has emerged nationwide as the optimal predictor of mixtures’ moisture damage susceptibility. This research compared what GDOT considers the two most accurate predictors of moisture damage susceptibility: (1) AASHTO T-324 Hamburg Wheel-Track Testing of Compacted Hot Mix Asphalt; and (2) GDT-66, Evaluating the Moisture Susceptibility of Bituminous Mixtures by Diametral Tensile Splitting, using a Hamburg wheel tracking device (HWTD) and diametral tensile strength apparatus, respectively. GDOT also retrofitted an Asphalt Pavement Analyzer (APA) to perform AASHTO T-324 by adding steel wheels for underwater testing. Plant produced samples and core specimens were tested to compare construction and post-construction characteristics, and WMA sample characteristics were also compared with control hot mix asphalt (HMA) samples. Significant effects of high asphalt cement (AC) content were observed on rut depths measured by the HWTD and APA; however, the same effects were not observed on retained strength values among the WMA samples, per GDT-66. A strong linear correlation was observed between the rates of rutting in samples tested with the HWTD and APA. Further study is recommended to investigate a possible correlation factor for these two rates.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK30 Characteristics of Nonasphalt Components of Asphalt Paving Mixtures.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Brandon, James
  • Hines, Sheila
  • Jared, David M
  • Bui, Binh H
  • Ahmed, Yusuf
• 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; Photos; References; Tables;
• Pagination: 17p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Asphalt cement; Hot mix asphalt; Moisture damage; Retrofitting; Rutting; Temperature; Warm mix paving mixtures
• Identifier Terms: Asphalt Pavement Analyzer; Georgia Department of Transportation; Hamburg Wheel Tracking Device
• Geographic Terms: Georgia
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01514797
• Record Type: Publication
• Report/Paper Numbers: 14-2938
• Files: TRIS, TRB, ATRI
• Created Date: Feb 21 2014 3:16PM