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https://nap.nationalacademies.org/catalog/27432/critical-issues-in-transportation-for-2024-and-beyond

Asphalt Mix Overlay Alternative for Low Volume Roads on the Local Transportation System

This research project aimed to identify or develop a practical method for designing a well-performing hot mix asphalt (HMA) for use on low-volume local roads with severe cracking that can be produced in existing asphalt plants and can be placed using conventional paving equipment available in Ohio. This research project was conducted in two phases. In Phase 1, a comprehensive literature review was conducted to identify mix design procedures that have been used to produce an asphalt mixture that is resilient to cracking and can withstand prevailing environmental conditions in Ohio. In addition, state and local transportation agencies in the United States were surveyed to document their current state-of-the-practice with regard to pavement resurfacing for low-volume roads. Medina County Highway Department (MCHD) reported using a recipe mix (Medina County Specification (CS) 402) that is resilient to cracking and can be produced and placed using conventional HMA plants and paving equipment. This asphalt mixture consisted mainly of 90% No. 57 limestone aggregates mixed with 10% natural sand. A PG 58-28 asphalt binder was used in this mixture at a binder content of 4.3%. This asphalt mixture is installed as an intermediate asphalt course followed by aggregate choking using No. 9 aggregates and chip sealing. A laboratory testing plan was designed and executed in Phase 1 to optimize the mix design of Medina CS 402. Based on the outcome of these laboratory tests, several modifications were proposed to Medina CS 402 for consideration in the field evaluations in Phase 2. These modifications included reducing the amount of No. 57 aggregates to 80% and increasing the amount of natural sand to 20%. In addition, it was recommended to increase the asphalt binder content to 4.8% or 5.3%. To validate the proposed modifications and further optimize the mix design of Medina CS 402, several pavement test sections were constructed using different material combinations at two test sites in Medina County and Franklin County. Based on the laboratory test results for the plant-produced asphalt mixtures that were collected during production, it was recommended to use an asphalt binder content of 5.3% for Medina CS 402. The laboratory test results obtained for the field-produced asphalt mixture containing crushed gravel suggested that this type of aggregate can be used as an alternative to limestone in this asphalt mixture. Therefore, either No. 57 limestone or No. 57 crushed gravel can be used for Medina CS 402. It was recommended to continue to monitor the performance of the field sections for the next three years to five years to determine if any changes in the mix design of the asphalt mixture are needed.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 51p

Subject/Index Terms

Filing Info

  • Accession Number: 01780927
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/OH-2021-14
  • Contract Numbers: 32411
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Aug 31 2021 11:18AM