Representative Testing of Expansive Soil Treatment Technologies for Transportation Earthworks

The shrink-swell behavior of expansive soils reduces transportation infrastructure longevity in much of the Mountain Plains region (Colorado, North Dakota, South Dakota, Utah, and Wyoming). Roadways are particularly susceptible to the effects of expansive soils due the combination of low ground pressures and large surface areas. The pervasiveness of expansive soils in the continental U.S. is shown in Fig. 1. Current estimates for the annual cost of damage to transportation infrastructure from expansive soils are not readily available, but were estimated by U.S. Housing and Urban Development (HUD) to be approximately $1.1 billion in 1973 (Jones & Holtz 1973) and $4.3 billion in 1981 (Jones 1981; $12 billion in 2017 dollars adjusting for inflation). Given the prevalence of expansive soils in the Mountain Plains region, economical solutions to mitigate damage to transportation infrastructure is necessary to enhance transportation system longevity throughout the Mountain Plains region. The current Mountain-Plains Consortium (MPC) project MPC-509 is aimed at evaluating expansive soil mitigation for transportation earthworks by polymer amendment. The goal of MPC-509 is to provide un-biased information on the effectiveness of commercially available polymer stabilizers. Testing to date has involved four commercially available polymer treatment technologies applied at different dosage rates to a highly expansive soil. Testing on the highly expansive soil has also been performed with varying dosages of Class-C fly ash, lime, and on untreated soil. Testing to date has included standard soil characterization, and tests of hydraulic conductivity (ASTM D5084), swelling potential (ASTM D4546), expansion index (ASTM D4829), and unconfined compressive strength (ASTM D5102). Results to date have shown that traditional stabilizers (lime and Class-C fly ash) are more effective at reducing swelling potential and expansion index than polymeric amendments. However, traditional stabilizers result in an order-of-magnitude increase in permeability, while polymer amendments result in reductions in permeability. Shrink-swell potential is mechanistically based on the addition of water, and the rate of ingress of water into soil is governed by the soil permeability. Thus, existing standard methods fail to provide a representative comparison of traditional and polymeric stabilizers (due to the ways these treatments modify the soils). An alternative method is needed to accurately compare traditional and polymeric stabilization of expansive soils, as well as other innovative materials proposed for use in treating expansive soils.


  • English


  • Status: Active
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Project Managers:

    Kline, Robin

  • Performing Organizations:

    Colorado State University

    Department of Civil and Environmental Engineering
    Campus Delivery 1372
    Fort Collins, Colorado  United States  80523
  • Principal Investigators:

    Scalia, Joseph

    Bareither, Christopher

  • Start Date: 20171102
  • Expected Completion Date: 20220731
  • Actual Completion Date: 0
  • Source Data: MPC-538

Subject/Index Terms

Filing Info

  • Accession Number: 01650579
  • Record Type: Research project
  • Source Agency: Mountain-Plains Consortium
  • Contract Numbers: 69A3551747108
  • Files: UTC, RiP
  • Created Date: Nov 6 2017 1:39PM