Leaching from Granular Materials Used in Highway Construction Intermittent Wetting

Many secondary materials are being considered for use as aggregate substitutes in highway construction applications. Such applications may include use of secondary materials as aggregate in road base, shoulders, embankments, and other fill applications. For these applications, leaching of constituents of concern during intermittent infiltration as a consequence of precipitation events is a primary potential pathway for environmental impact during use and subsequent disposal. The overall goal of this project is to develop testing and interpretation protocols to estimate constituent leaching from granular waste materials that are utilized as aggregate in highway construction applications. The resulting test methods and interpretation protocols, including appropriate mathematical models, can then be used to evaluate environmental impact of specific proposed secondary material utilization applications through the leaching pathway. The primary focus will be on leaching conditions that occur as a consequence of intermittent infiltration into the granular material. The resulting constituent release mechanisms are by (a) percolation through the granular material, and (b) mass transfer from the secondary material to surrounding materials (e.g., underlying soil) by either capillary flow or diffusion, when percolation is not occurring. Motivation for end-users to adopt the protocols will be based on the need to evaluate potential environmental impacts for both liability and regulatory assessment.

Language

• English

Project

• Status: Active
• Contract Numbers:

  Research Project 11

• Sponsor Organizations:

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  University of New Hampshire, Durham

  Recycled Materials Resource Center
  Environmental Technology Building, 35 Colovos Road
  Durham, NH  United States  03824
• Performing Organizations:

  Environmental Protection Agency

  401 M Street, SW
  Washington, DC  United States  20460

  University of New Hampshire, Durham

  Recycled Materials Resource Center
  Environmental Technology Building, 35 Colovos Road
  Durham, NH  United States  03824
• Start Date: 20020901
• Expected Completion Date: 0
• Actual Completion Date: 0
• Source Data: RiP Project 8079

Subject/Index Terms

• TRT Terms: Concrete; Construction; Highways; Leaching; Mathematical models; Research projects
• Subject Areas: Construction; Highways; Research; I30: Materials;

Filing Info

• Accession Number: 01459192
• Record Type: Research project
• Source Agency: University of New Hampshire, Durham
• Contract Numbers: Research Project 11
• Files: RIP, USDOT
• Created Date: Jan 3 2013 12:58PM