A New Generation of Dense-Graded Asphalt Mixtures with Superior Performance against Stripping and Moisture Damage

The presence of moisture in a pavement structure is a matter of great concerns as it is responsible for significant distresses such as stripping, fatigue cracking, rutting, and poor durability. Asphalt concrete (AC) stripping, which is a chronicle problem in flexible pavements in Louisiana and Arkansas, refers to the loss of bond between the aggregate and asphalt binder usually caused by the accumulation of moisture underneath the pavement surface. In Louisiana, shallow groundwater table (GWT) and heavy rainfall conditions (average annual rainfall of 60 in.) throughout the year make the pavement highly vulnerable to water entrapment and moisture damage. The effect of AC stripping is manifested in the roadway through poor durability of the mixes and shorter service life. These pavement distresses greatly affect user safety, pavement performance, and cost-effectiveness of maintenance and rehabilitation activities. Research results by the PI showed that pavement service life, the average performance increase, and cost-effectiveness decreased significantly when a chip seal was applied on moisture-damaged pavements. Similar results were observed for AC overlays as overlaying extended pavement service life by 13 years when placed on non-stripped pavements but only performed adequately for 8.7 years when moisture damage was present in the underlying AC layers. The objective of this research is to develop a new generation of dense-graded asphalt mixtures that would provide superior performance against AC stripping and moisture damage. To develop this improved asphalt mixture, the current state of practice including aggregate type and gradation, and additives, will be reviewed and comprehensively evaluated. Furthermore, innovative ideas will be evaluated in the laboratory including the use of hydrophobic nanomaterials and emerging anti-stripping agents such as Evotherm and vegetable-based oils, recycled products such as crumb-rubber, warm-mix asphalt technologies, and adhesion promotors. For promising technologies, the research team will ensure that the new generation of asphalt mixtures will be environmentally friendly and cost-effective by testing and evaluating different additive types, recycled products, and other additives such as nanoclay and super-fine hydrated lime. The scope of this project includes two phases, namely Research and Implementation. The Research Phase involves the technical aspects of the project and will consist of two main stages. First, the study will review the current state of practice in designing and producing asphalt mixtures in Louisiana and Arkansas. The reasons for the frequent appearance of AC stripping will be investigated and identified. Second, the study will develop a new generation of asphalt mixes that would address the identified causes of AC stripping in asphalt pavements. The developed mixes will be cost-effective and environmentally-friendly. On the other hand, the Implementation Phase will focus on the technology transfer, education and workforce development, and outreach activities of the project.

• Supplemental Notes:
  • 21BLSU03

Language

• English

Project

• Status: Active
• Funding: $135000
• Contract Numbers:

  69A3551747106

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Managing Organizations:

  Transportation Consortium of South-Central States (Tran-SET)

  Louisiana State University
  Baton Rouge, LA  United States  70803
• Project Managers:

  Mousa, Momen

• Performing Organizations:

  Louisiana State University, Baton Rouge

  P.O. Box 94245, Capitol Station
  Baton Rouge, LA  United States  70803
• Principal Investigators:

  Elseifi, Mostafa

  Hossain, Zahid

• Start Date: 20210801
• Expected Completion Date: 20230201
• Actual Completion Date: 0
• USDOT Program: University Transportation Centers Program

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Dense graded aggregates; Durability; Pavement performance; Stripping (Pavements)
• Subject Areas: Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01833035
• Record Type: Research project
• Source Agency: Transportation Consortium of South-Central States (Tran-SET)
• Contract Numbers: 69A3551747106
• Files: UTC, RIP
• Created Date: Jan 20 2022 2:14PM