This article describes several recently completed or ongoing research projects pertaining to recycling in highway construction. The projects, which are national in scope, were sponsored by the Federal Highway Administration (FHWA) or the National Cooperative Highway Research Program (NCHRP). The development of the "User Guidelines for Waste and Byproduct Materials in Pavement Construction" began in 1996. The primary objective of the project was to assess the state of the practice of using waste or byproduct materials in pavement construction and to produce a guidance manual for a variety of interested parties, including state and local transportation agencies, environmental agencies, waste generators and recyclers, design engineers, and contractors. In 1997, four FHWA recycling research projects were initiated through cooperative agreements with a consortium headed by the University of New Hampshire. They examined the following topics: residual alkali-silica reaction potential in existing portland cement concrete, mix design for cold in-place recycling, evaluation of the use of recycled materials, and predicting long-term environmental performance. The development of the Recycled Materials Information Database (NCHRP 4-21) began in 1998. The primary objective of the project was to provide a tool that could be used to store data about recycled material properties, applications, testing procedures, and reference information. The recently completed NCHRP study (NCHRP 25-9), Environmental Impact of (Highway) Construction and Repair Materials on Surface and Ground Waters, was directed to determine whether commonly used construction and repair materials might affect the quality of surface and ground waters. The objective of the study was to evaluate the persistence of any toxic leachates of the selected materials and to estimate the possible impacts of these materials on surface and ground waters.


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  • Accession Number: 00797245
  • Record Type: Publication
  • Files: TRIS, USDOT
  • Created Date: Aug 23 2000 12:00AM