Long-Term Corrosion Monitoring in Mechanically Stabilized Earth (MSE) Walls

Details

• Creators:
  Kulesza, Stacey ; Parsons, Robert ; Liu, Hao ; Han, Jie
• Corporate Creators:
  Kansas State University Transportation Center ; University of Kansas
• Corporate Contributors:
  Kansas. Department of Transportation. Bureau of Materials and Research
• Subject/TRT Terms:
  Aggregates Corrosion Galvanizing Mechanically Stabilized Earth Reinforcing Materials Soil Stabilization
• Publication/ Report Number:
  K-TRAN: KSU/KU-21-3
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Kansas
• Edition:
  Final Report: August 2020–December 2022
• Corporate Publisher:
  Kansas State University. Transportation Center ; University of Kansas
• Abstract:
  This research is a continuation of K-TRAN: KSU-19-5. Mechanically stabilized earth (MSE) walls with metallic reinforcement are widely used as a cost-effective means of earth retention. Metallic reinforcement, which is susceptible to corrosion, is typically sized for a 75-year design life after allowing for a standard rate of corrosion. The Kansas Department of Transportation (KDOT) has many walls that have completed more than one-third of their design life. The previous study measured backfill corrosion conditions for 12 MSE walls selected by KDOT. The walls were surveyed by cutting through the wall face, sampling the backfill, and inspecting reinforcing strip conditions. The current study utilized a similar approach to validate a new field method for monitoring backfill conditions and to establish the current conditions of MSE walls selected by KDOT. In this study, 18 MSE walls were selected, six of which were surveyed in the previous study. In general, the field resistivity method and the physical sampling method consistently identified backfills with poor conditions. The results support the use of a modified four-electrode electrical resistivity measurement to identify backfill with high in situ moisture, high percent fines, and high levels of chlorides, which all lead to high corrosivity. Furthermore, this study documents the current conditions of the 18 walls, including unique photos of exposed reinforcement. Results from the physical testing of backfills showed that the finest fraction of the backfill (D10) was strongly correlated with low resistivity values, particularly for sand backfills. High chloride concentrations were also measured in the samples with the lowest resistivity. These results support the current recommendation that the percentage of fines (material smaller than the #200 sieve) be limited to a maximum of 5% and encourage the consideration of an additional specification that the percentage passing the #100 sieve be limited to 10%.
• Format:
  PDF
• Funding:
  C2164 ; C2170
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:29b5df7b08f30d7d1f6d0b67256a82c0ec60e8f3f321222f77e0d16413f7443bcf0890a4dd4c296bf903cc2671a162ef61b733324c36bdab43f83b70ae0eddf5
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/86791/dot_86791_DS1.pdf
• File Type:
  [PDF - 14.43 MB ]