Evaluation of Recycled Plastic Products in Terms of Suitability for Stabilization of Earth Slopes

Soil nailing has become a popular technique for stabilizing earth embankments. In general, steel pins (nails) are driven deep into the soil and then are connected to an outer layer such as shotcrete over a wire mesh. The nails reinforce the soil, supporting tensile loads and creating a stronger soil mass overall. Soil nailing is a fast, effective method for stabilizing new cuts or strengthening older slopes. Missouri DOT (MoDOT) and the University of Missouri-Columbia (UMC) are in Phase II of a three- phase project to evaluate plastic pins made from recycled plastics as a replacement for steel pins. Phase I of the project demonstrated that plastic pins successfully stabilized a slope near Emma, Missouri. Phase II is expanding the demonstration to an additional four to six sites. However, MoDOT has encountered a problem in that there are dozens of manufacturers that produce plastic pins using different material formulations and processing techniques. This results in significant variability in the engineering properties of different pins. Furthermore, there are no common specifications for quantifying and reporting pin performance, so that different manufacturers characterize their pins using different tests. To solve this problem, MoDOT and UMC will conduct uniform lab-oratory and field tests on different pins so that their properties can be directly compared. In the laboratory, uniaxial compression, 4-point bending and accelerated creep tests will be used to characterize the mechanical behavior of the material (i.e., strength, stiffness, creep, etc.). These tests will be followed by field tests to evaluate the key issue of "drivability," or how well the nails can be inserted into the soil. Once the research is complete, a new phase will begin that will focus on collecting the data and field experiences into standards and guidance documents. This is a new project that started in August 2002.

Language

• English

Project

• Status: Active
• Contract Numbers:

  Research Project 24

• 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:

  University of Missouri, Columbia

  Agricultural Experiment Station
  Columbia, MO  United States  65201

  University of New Hampshire, Durham

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

  Fennessey, Thomas

• Start Date: 20020801
• Expected Completion Date: 0
• Actual Completion Date: 0
• Source Data: RiP Project 8093

Subject/Index Terms

• TRT Terms: Earthwork; Embankments; Recycled materials; Research projects; Shotcrete; Slope stability; Soil nailing; Wire mesh
• Subject Areas: Construction; Research; I30: Materials;

Filing Info

• Accession Number: 01459181
• Record Type: Research project
• Source Agency: University of New Hampshire, Durham
• Contract Numbers: Research Project 24
• Files: RIP, USDOT
• Created Date: Jan 3 2013 12:58PM