Implementation of New Specifications Requirements for Coarse Backfill Materials for Mechanically Stabilized Earth (MSE) Walls

The service life of mechanically stabilized earth (MSE) walls depends on the rate of corrosion of the metal reinforcements used in their construction. Assessment of corrosion potential requires the accurate evaluation of pH, resistivity, and ionic (e.g., sulfate and chloride) concentrations of aqueous solutions in contact with the surrounding aggregate. There is a tendency to utilize larger-size aggregates that contain only a small amount of fine material (passing No. 40 sieve) in the backfill. Evaluation of the electrochemical parameters of coarse aggregates is challenging because traditional methods utilize only fine-grained material. Testing demonstrated that the fines collected from the field were enriched in chemicals that when exposed to water decreased pH and resistivity and increased chloride or sulfate concentrations relative to the bulk rock. This phenomenon can bias traditional soil testing results and therefore the assessment of corrosion potential. A more representative and appropriate geochemical testing protocol is recommended by Texas Department of Transportation (TxDOT) research project 0-6359: Characterization of Backfill Materials for Prevention of Corrosion of MSE Wall Metallic Earth Reinforcement which concluded August 31, 2012.

• Record URL:
  http://library.ctr.utexas.edu/Presto/content/Detail.aspx?ctID=M2UxNzg5YmEtYzMyZS00ZjBlLWIyODctYzljMzQ3ZmVmOWFl&rID=NDA4&sID=MQ==&qrs=VHJ1ZQ==&q=KCop&qcf=M2UxNzg5YmEtYzMyZS00ZjBlLWIyODctYzljMzQ3ZmVmOWFl

Language

• English

Project

• Status: Completed
• Funding: $365000
• Contract Numbers:

  5-6359-01

• Sponsor Organizations:

  Texas Department of Transportation

  125 E. 11th Street
  Austin, TX  United States  78701-2483
• Project Managers:

  Steele, Joanne

• Performing Organizations:

  The University of Texas at El Paso

  500 W University Ave
  El Paso, TX  United States  79902
• Principal Investigators:

  Nazarian, Soheil

• Start Date: 20150814
• Expected Completion Date: 20180831
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Backfill soils; Backfilling; Coarse aggregates; Corrosion; Earth walls; Electrochemical processes; Mechanically stabilized earth; Specifications; Test procedures
• Geographic Terms: Texas
• Subject Areas: Construction; Geotechnology; Highways;

Filing Info

• Accession Number: 01634639
• Record Type: Research project
• Source Agency: Texas Department of Transportation
• Contract Numbers: 5-6359-01
• Files: RIP, STATEDOT
• Created Date: May 11 2017 4:25PM