BACKGROUND
Cracking is one of the primary distress modes driving the need for rehabilitation of asphalt pavements. Numerous factors including traffic loading, environmental effects, and material selection influence the development of the most common modes of asphalt pavement cracking (low-temperature, reflection, fatigue, and top-down). State departments of transportation (DOTs) have recognized the need to establish and implement practical and reliable performance-related tests that can be used to evaluate cracking performance and use the test results to select asphalt mixtures more appropriately.
NCHRP Project 09-57 was established to provide a sound basis for recommending the tests most suitable to determine cracking resistance and its corresponding predicted performance using an incremental approach.
Initially, NCHRP Project 09-57, “Experimental Design for Field Validation of Laboratory Tests to Assess Cracking Resistance of Asphalt Mixtures,” developed experimental designs for the ruggedness testing of candidate laboratory tests to assess the resistance of asphalt mixes to four cracking types. The findings of this research can be found in NCHRP Research Results Digest 399: Field Validation of Laboratory Tests to Assess Cracking Resistance of Asphalt Mixtures: An Experimental Design.
Subsequently, Phases I and II of NCHRP Project 09-57A, “Ruggedness of Laboratory Tests to Assess Cracking Resistance of Asphalt Mixtures,” produced NCHRP Research Report 987: Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance, and recommended three levels of laboratory cracking tests for field validation based on the availability of resources.
Later, based on the cracking tests identified in NCHRP Research Report 987, Phase III of NCHRP Project 09-57A assessed the availability of materials and pavement performance data of the Long-Term Pavement Performance (LTPP) program and the 2008 MnROAD pavement sections to potentially use them for field validation of the tests.
With this information now available, research is needed to conduct the field validation of the laboratory cracking tests and for establishing corresponding performance-related criteria.
OBJECTIVE
The objective of this research is the field validation of laboratory cracking tests and establishing corresponding performance criteria utilizing laboratory-mixed and laboratory-compacted specimens.
The field validation and performance criteria shall be primarily based on the previous findings of the NCHRP Project 09-57 phases: NCHRP Research Results Digest 399, NCHRP Research Report 987, and the NCHRP Project 09-57A contractor’s final report.
RESEARCH PLAN
At a minimum, the anticipated tasks include:
- Perform a critical review of NCHRP Research Report 987, NCHRP Research Results Digest 399, and the NCHRP 09-57A contractor’s final report.
- Conduct a critical literature review of research that can contribute to the accomplishment of the research objective. The review shall include published and unpublished research conducted through the NCHRP; FHWA; and other national, international, state, and pooled-fund sponsored research. Synthesize the results in Technical Memorandum No. 1.
- Based on the proposer’s experience, and the available data, mixture materials, and budget, develop a work plan to meet the research objective. The plan must address the validation of cracking test(s) and corresponding performance criteria as budget permits, or in recommendations for future research. Include the rationale used to support the feasibility and development of the work plan, the selected test(s), and mixture materials. Submit Interim Report No.1. The proposer will need NCHRP approval of Interim Report No. 1 before proceeding with the project.
- Execute the approved work plan to validate the cracking test(s) and performance criteria. Submit Interim Report No. 2. Interim Report No. 2 must document the research work thus far and present an annotated outline of the final deliverables.
Anticipated deliverables for this project include:
1. A conduct of research report documenting the project activities and results. The report shall include a table with the covered test(s) with corresponding performance criteria.
2. A technical memorandum titled “Implementation of Research Findings and Products”.
STATUS: Research in progress.