Durability of Pipe Materials in Soils

A large number culvert pipes are installed every year in North Carolina. While the loading and structural requirements for these pipes are considered during the selection process, the exposure condition of these culverts receives less attention. Many pipe choices exist including reinforced concrete, galvanized steel, aluminum, aluminized, and various types of plastic. Choosing the right pipe for the right installation is a non-trivial task that carries significant financial impact. Factors such as structural capacity, environmental durability, anticipated life-span, required pipe size, site conditions, and available construction expertise are all important when selecting a pipe. Existing NCDOT selection tables provide some limited guidance, but often result in highly-conservative selections being made, particularly from the perspective of matching pipe materials to site environmental conditions. Selection of the wrong pipe material (or an overly-conservative pipe material) can result in significant excess cost. If materials degrade too quickly, costly re-work is required, and additional costs and risks may be incurred due to reduced performance of the degraded pipe. If high-cost and high-performance materials are selected in areas where they are not needed, then initial construction costs can increase dramatically. For example, in many situations, aluminized corrugated steel pipe can likely provide the same useful service life as corrugated aluminum pipe at a dramatically reduced cost. Aluminum pipe may be justified in regions with salt-water exposure, however, it is likely an overconservative choice for regions where contact with salt will be incidental. Accounts from NCDOT personnel have indicated widespread use of aluminum pipe in regions where it is likely not needed (i.e., regions with limited salt exposure). Given current limitations in the information available to support the selection of pipe materials, more detailed and elaborate selection criteria are needed. These criteria should account for exposure conditions such as the presence of salt, the soil pH, and the possible presence of contaminants, including more common contaminants such as fertilizers. In addition, factors such as installation requirements (e.g., slope), resistance to fire, and the potential for future disposal need to be considered. Finally, the required service life should be factored into pipe material selection. In some instances, the required service life can be short due to expected future development, while in other instances, the required service life can be 30 years or more.

    Project

    • Status: Active
    • Funding: $299,710
    • Sponsor Organizations:

      North Carolina Department of Transportation

      Research and Development
      1549 Mail Service Center
      Raleigh, NC  United States  27699-1549
    • Managing Organizations:

      North Carolina Department of Transportation

      Research and Development
      1549 Mail Service Center
      Raleigh, NC  United States  27699-1549
    • Project Managers:

      Kirby, John

    • Performing Organizations:

      North Carolina State University

      Department of Civil, Construction and Environmental Engineering
      2501 Stinson Drive
      Raleigh, NC  United States  27695
    • Principal Investigators:

      Pour-Ghaz, Mohammad

    • Start Date: 20190801
    • Expected Completion Date: 20210731
    • Actual Completion Date: 0

    Subject/Index Terms

    • TRT Terms: Pipe
    • Subject Areas: Bridges and other structures;

    Filing Info

    • Accession Number: 01716171
    • Record Type: Research project
    • Source Agency: North Carolina Department of Transportation
    • Files: RiP, STATEDOT
    • Created Date: Sep 16 2019 3:20PM