Development of a Job Mix Formula and QC/QA Framework for NCDOT Chip Seals
Chip seals are among the most efficient and cost-effective methods utilized by state highway agencies to preserve and rejuvenate existing pavements. Chip seal operations in North Carolina have been outsourced since their transfer from the North Carolina Department of Transportation's (NCDOT's) internal Road Oil program about 12 years ago. Some large contracting firms have developed the sufficient skills and experience needed to construct chip seals, but quality-related problems, such as raveling and too much fine material and moisture in the aggregate, have been found in some jobs. Quality control (QC) and quality assurance (QA) is an important step toward ensuring that pavements perform satisfactorily, and a job mix formula (JMF) designed specifically for chip seals is the first step toward well performing chip seals, which is currently lacking in the NCDOT chip seal specifications. A series of chip seal research projects conducted at North Carolina State University (NCSU) can provide an excellent foundation for the development of a JMF for NCDOT chip seals. Findings from these projects cover a wide range of critical elements in developing a chip seal JMF, including the aggregate gradation and maximum fine content, emulsion performance graded specifications, performance test methods, and performance-based mix design method. The primary goal of the proposed research project is to develop a JMF for chip seals constructed in North Carolina. The scope of the proposed research includes double seals with granite and lightweight aggregates; however, the findings from the proposed research can be applied to single and triple seals as well. The research plan includes the characterization of different aggregate types with varied gradations, the characterization of emulsions using the test procedures currently used in the NCDOT specifications and procedures recommended by the NCHRP 09-50 project, the evaluation of aggregate-emulsion compatibility, chip seal performance testing, refinement of NCSU's chip seal mix design method, and development of a chip seal JMF and QC/QA framework for the NCDOT using performance test data obtained from laboratory tests. The research products from the proposed project will result in improved control over chip seal design and construction compared to the current practice, enhanced chip seal performance, prolonged chip seal service life, decreased life cycle costs, improved NCDOT chip seal specifications, and potentially reduced carbon footprint.
Language
- English
Project
- Status: Active
- Funding: $277,671.00
-
Contract Numbers:
RP2027-02
-
Sponsor Organizations:
North Carolina Department of Transportation
Research and Development
1549 Mail Service Center
Raleigh, NC United States 27699-1549 -
Managing Organizations:
North Carolina Department of Transportation
Research and Development
1549 Mail Service Center
Raleigh, NC United States 27699-1549 -
Project Managers:
Kadibhai, Mustansir
-
Performing Organizations:
North Carolina State University, Raleigh
Department of Civil Engineering, Campus Box 7908
Raleigh, NC United States 27695-7908 -
Principal Investigators:
Castorena, Cassie
- Start Date: 20260801
- Expected Completion Date: 20280731
- Actual Completion Date: 0
- USDOT Program: Pavements and Materials
- Subprogram: pavement maintenance
Subject/Index Terms
- TRT Terms: Chip seals; Mix design; Pavement performance; Quality assurance; Quality control
- Geographic Terms: North Carolina
- Subject Areas: Highways; Maintenance and Preservation; Materials; Pavements;
Filing Info
- Accession Number: 01995056
- Record Type: Research project
- Source Agency: North Carolina Department of Transportation
- Contract Numbers: RP2027-02
- Files: RIP, STATEDOT
- Created Date: Jul 9 2026 8:42AM