Rapid field detection of sulfate and organic content in soils : technical report.

Details

• Creators:
  Harris, Pat ; Harvey, Omar ; Sebesta, Stephen
• Corporate Creators:
  Texas Transportation Institute
• Corporate Contributors:
  Texas. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Soils--Sulfur Content--Measurement Soils By Organic Content Soil Stabilization Soil Stabilization--Measurement Sulfur
• Publication/ Report Number:
  FHWA/TX-11/0-6362-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Edition:
  Technical report; Sept. 2009-Aug. 2010.
• Corporate Publisher:
  Texas Transportation Institute
• Abstract:
  In recent years, the Texas Department of Transportation (TxDOT) has experienced problems chemically
  
  stabilizing moderate to high plasticity clay soils with calcium-based additives. Many of the problems are the
  
  result of soluble sulfate minerals in the soil reacting with the lime or cement added for stabilization. The
  
  occurrence of these deposits is unpredictable and often restricted to small areas. To address this problem,
  
  the researchers set about identifying a technique that provides a map showing the sulfate content of the soil
  
  over a large area to a depth of 3 to 4 ft. Two technologies were identified that provide an indirect
  
  measurement of sulfate salts (an electromagnetic device – EM-38, and a soil conductivity device – VERIS
  
  3150). We tested these devices on three different TxDOT projects in different parts of the state that have
  
  been known for high sulfate contents. We collected soil samples at 1 ft intervals to a depth of 4 ft where the
  
  data varied. We measured the PI, moisture content, sulfate content, and organic content in each sample. We
  
  then ran multivariate statistical analyses to correlate the conductivity data collected with the VERIS 3150 to
  
  laboratory-measured soil properties. We observed that soil conductivity is related to the soil texture/clay
  
  content, moisture content, and dissolved salts (i.e., sulfate and other salt minerals). We noted that for all of
  
  the projects tested, a soil conductivity over 100 mS/m may contain problematic sulfate levels, but it may also
  
  be due to high plasticity clay soils and/or high moisture contents with other dissolved salts. What is
  
  noteworthy about this research is it provides a tool to intelligently decide where to collect soil samples to
  
  analyze for problematic sulfate levels versus the current method of collecting soil samples in a grid pattern of
  
  a specified interval that may be too large and not detect problematic sulfate levels until the road explodes.
  
  
• Format:
  PDF
• Funding:
  Project 0-6362
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:467216fdb06c56eb9e9ec407a86f858007d82e852087bd08808e68ffab50497e06b3ea9f9cb812f6449baab2683675fd23cc0dc8e1f77139ff2205aa1b38e90d
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/20944/dot_20944_DS1.pdf
• File Type:
  [PDF - 4.93 MB ]