Field evaluation of hardening methods for subsurface utilities and drainage pipes

The North Carolina Department of Transportation (NCDOT) routinely performs road improvement projects where a portion of the right-of-way might be contaminated. Based on the field evaluations carried out by NCDOT, at times subsurface utilities including water and/or drainage pipes are present, or need to be installed, in environments where soil and groundwater contamination exists. The currently funded project is focused on the laboratory evaluation of contaminant migration through concrete pipes, as well as evaluation of the effect of contaminants on the mechanical performance of PVC pipe and three gasket materials (Neoprene, Buna-N, and Viton) when exposed to contaminated water. In addition, modeling of hardening methods and evaluating their efficacy is conducted as a part of the ongoing project. The work proposed herein is focused on field studies that will assess the effectiveness of hardening methods for reducing contaminant migration into subsurface pipes. In field installations, and as a colleague at NCDOT described, the performance of materials is affected by many factors such as groundwater flow, seasonal changes in water table, temperature gradients, the ability of the soil to biodegrade contaminants, etc. The main objective of the proposed research is to quantify the performance of hardening methods installed in the field in terms of eliminating contaminant migration into the pipes. Specifically, the proposed project aims at the following: (i) field measurement of contaminant migration through Neoprene, Buna-N, and Viton gaskets at locations where such gaskets are installed, and (ii) field measurement of contaminant migration through PVC and HDPE membranes used for wrapping concrete materials as hardening method. In collaboration with NCDOT colleagues, project locations in the Coastal Plain, the Piedmont, and the Mountains physiographic regions will be identified, where subsurface utilities and drainage pipes have been installed in contaminated subsurface profiles. Monitoring “capsules” equipped with the same hardening method (e.g., wrapping materials, or gasket materials) used for the pipeline utilities will be installed parallel to the pipelines. Six, twelve, and eighteen months after the field installation, the capsules will be taken out and will be analyzed for contaminant breakthrough and migration. In parallel, sites, where the capsules are installed will be numerically modeled including the unsaturated and saturated zones. The field performance data, coupled with the modeling results, will provide quantitative measures on the effectiveness of different hardening methods and their comparative performance, reducing the uncertainty with regard to their performance and helping to identify the most economical hardening strategy. Data from this research can used to develop robust specifications, and provide direction as to advantages of wrapping, using alternative pipe material, or installing specific gasket material, for example.


    • English


    • Status: Completed
    • Funding: $336834
    • 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, Raleigh

      Department of Civil Engineering, Campus Box 7908
      Raleigh, NC  United States  27695-7908
    • Principal Investigators:

      Pour-Ghaz, Mohammad

    • Start Date: 20190801
    • Expected Completion Date: 20210731
    • Actual Completion Date: 20211231

    Subject/Index Terms

    Filing Info

    • Accession Number: 01716167
    • Record Type: Research project
    • Source Agency: North Carolina Department of Transportation
    • Files: RIP, STATEDOT
    • Created Date: Sep 16 2019 2:33PM