Final Scope

Existing flexible pavement maintenance programs of many state departments of transportation (DOTs) typically involve two kinds of activities: sealing cracks and patching. However, the strategies employed by maintenance crews depend on the width and the severity of the crack and the underlying pavement structure.

Wide flexible pavement cracks are frequently larger than those typically repaired by crack or joint sealing efforts but are smaller than repairs requiring remove-and-replace patching procedures.

Repairs of these types of distresses with materials such as flexible asphalt-based mastics, sand asphalt, or other patching materials have been shown to extend pavement service life. Engineered products, such as mastics, typically consist of polymer or rubber-modified asphalt binder systems combined with mineral fillers or fine aggregates. Experience has shown that engineered products can provide substantially better performance than more traditional solutions, such as sand asphalt, for wide flexible pavement cracks. Mastic-type materials may be combined with repair techniques such as micro-milling or routing to remove loose pavement material and provide an adequate reservoir to receive the repair material. State DOTs have developed evaluation and approval programs for assessment of available and emerging maintenance materials, and methods of application.

The objective of this synthesis is to document practices used by state DOTs for flexible and composite pavement maintenance for wide transverse and longitudinal cracks and joints.

Information to be gathered includes (but is not limited to):

• Products and methods utilized; 
• Cost data for different treatment methods and materials;
• When does the crack become large enough that traditional sealing is not advisable;
• Written policies, definitions, specifications, decision processes, and guidelines related to treatments of wide cracks and joints;
• Do you perform cost-effectiveness analysis to select treatment methods;
• Application records (e.g., year, pavement type, traffic, or condition) from different climatic zones;
• Impact of different applications and treatments on pavement service life, treatment cost and benefits, and performance measures such as ride quality, noise, and skid resistance;
• Written procedures for acceptance and quality assurance of new or current maintenance materials (e.g., testing, inspection, or traceability); and
• Performance records of related pavement maintenance products and techniques for wide cracks.

Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.

Information Sources (Partial):

• ASTM D8260. Standard Specification for Hot-Applied Asphalt Aggregate-Filled Mastic. American Society of Testing and Material, Philadelphia, Pennsylvania, 2020.
• Hajj, R., and Lu, Y., (2021). Current and Future Best Practices for Pothole Repair in Illinois. Springfield: Illinois Center for Transportation.
• Tons, E., and Khuri, M. F. Mastic Asphalt for Maintenance. Michigan Department of Transportation (MDOT), 1987.
• Michigan Department of Transportation (MDOT), (2019). Capital Preventive Maintenance Specifications.
• Minnesota Department of Transportation (MnDOT), (2019). MnDOT Pavement Preservation Manual.
• Washington State Department of Transportation (WsDOT), (2020). Maintenance Manual M 51-01.11.

TRB Staff (consultant)
Sandra Larson
Phone: 515-971-6329
Email: slarson@nas.edu

Meeting Dates
First Panel: October 3, 2023, Washington, DC
Teleconference with Consultant: October 26, 2023, 3-4 pm Eastern
Second Panel: June 5, 2024,10:00 am-4 pm, Washington DC, Keck Center

Panel Members

Amy Beise, North Dakota Department of Transportation
Steve Cooper, Federal Highway Administration (FHWA)
Anita Bush, Nevada Department of Transportation
Ohhoon Kwon, Florida Department of Transportation
Tommy Nantung, Indiana Department of Transportation
Michael Rossi, New York State Department of Transportation
Tyson Rupnow, Louisiana Department of Transportation and Development
Robert Younie, Iowa Department of Transportation
Ilona Kastenhofer, Transportation Research Board