BACKGROUND
As the field of asphalt technology advances, many agencies are transitioning to balanced mix design (BMD) methodologies and integrating performance testing to enhance the quality and durability of asphalt mixtures. This shift has highlighted a critical need for uniformity in the handling, sample preparation, and storage of asphalt mixtures and test specimens. A key gap identified in NCHRP Synthesis 552: Practices for Fabricating Asphalt Specimens for Performance Testing in Laboratories is the impact of storage practices on the performance characteristics of asphalt mixtures.
Currently, there are no standardized protocols for the storage of loose asphalt mixtures and compacted specimens, leading to variability in test results and potential discrepancies in performance data. Without a unified approach to sample storage, conflicts can arise, undermining the reliability and comparability of performance test results across different agencies and laboratories. Research is needed to develop standardized storage requirements and procedures for asphalt mixtures and specimens used in performance tests to ensure the consistency and reliability of the test results.
OBJECTIVE
The objective of this research is to develop guidelines for standardized practices in the storage procedures of loose asphalt mixtures and compacted specimens.
Accomplishment of the project objective will require at least the following tasks.
TASKS
PHASE I – Planning
Task 1. Collect and review domestic and international literature, research findings, and information relevant to the effects of storage time and condition (e.g., type of container, sealed vs. unsealed container, storage location, temperature, humidity, etc.) for loose mixtures and compacted specimens on the performance properties of various asphalt mixtures. The review should consider factors such as current agency practices from sampling to performance testing. This information may be obtained from published and unpublished information and contacts with public and private organizations.
Task 2. Based on the review performed in Task 1, identify and evaluate the critical factors associated with the storage time and condition that affect asphalt mixture performance tests. These issues should be addressed in the final product or the recommended future research, as budget permits.
Task 3. Based on the work performed in Tasks 1 and 2, prepare a detailed work plan to be executed in Phase II and Phase III to:
- Evaluate the impact of the critical factors associated with the storage time and condition;
- Prepare draft language for consideration by American Association of State Highway and Transportation Officials (AASHTO) to incorporate the research results into a future edition of the AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing, and AASHTO Provisional Standards (herein called the Proposed Guidelines); and
- Prepare supplementary material to support adoption and implementation.
The plan shall provide specific information on the different aspects of the proposed work. It is expected that the work plan will include an experimental investigation.
Task 4. Prepare Interim Report No. 1 that documents the research performed in Tasks 1 through 3 and provides an updated work plan for the remainder of the research. The updated plan must describe the process and rationale for the work proposed for Phases II and III.
PHASE II – Execution
Task 5. Execute the research plan according to the approved Interim Report No. 1. Based on the results of this work, prepare and submit a preliminary draft of the Proposed Guidelines.
PHASE III – Final Deliverables
Task 6. Review and consider the comments on the preliminary draft of the Proposed Guidelines and prepare a draft version of the Proposed Guidelines.
Task 7. Prepare a document illustrating the impacts of the Proposed Guidelines to stakeholders.
Task 8. Prepare a stand-alone technical memorandum titled “Implementation of Research Findings and Products” to facilitate implementation of the Proposed Guidelines.
Task 9. Prepare presentation material, in a PowerPoint or other format, for use in webinars to facilitate the use and adoption of the Proposed Guidelines.
Task 10. Submit final deliverables including (1) a final report that documents the entire research effort, (2) the Proposed Guidelines, (3) the impacts of the Proposed Guidelines to stakeholders document, (4) the Implementation of Research Findings and Products, and (4) the presentation material.
STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.
