Use of Modified Moisture Barrier to Reduce Subsurface Moisture in Flexible Pavement in North Texas

Pavement serviceability can be reduced as the result of seasonal climatic variations in subgrade soil. Variations in moisture may alter material properties as well as cause shrinking and swelling in expansive subgrade. Current study reflects twofold objectives: (1) establish the rationale of selecting a modified moisture barrier to arrest moisture from entering subgrade; and (2) observe the benefits of the selected barrier with respect to preventing moisture variation in subgrade. The modified moisture barrier that is used in this study is a combination of a 40 mil LLDPE geomembrane (Linear Low Density Polyethylene) and 8 oz HDPE geocomposite (High Density Polyethylene). Based on the observation of edge moisture intrusion, the moisture barrier consisting of a geomembrane and a geocomposite (geonet sandwiched between two nonwoven geotextiles) was placed in a 50 ft section in FM 987 in Kaufman County, Texas. Additionally, a control section along the same roadway was instrumented and monitored for comparison. Variations in subgrade moisture content were monitored using in-situ moisture sensors and geophysical testing in the form of Electrical Resistivity Imaging (ERI). Deflections and moisture contents are continuously monitored in both the barrier section and the control section. The field monitoring results clearly indicated that the moisture barrier significantly reduced the water infiltration near the edge of the pavement. Moreover, the movement of the pavement is reduced by 80% than it is recorded in the control section.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFS60 Standing Committee on Subsurface Drainage.
• Authors:
  • Ahmed, Asif
  • Hossain, Md Sahadat
  • Khan, Mohammad Sadik
  • Greenwood, Kelli
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 21p

Subject/Index Terms

• TRT Terms: Flexible pavements; Geomembranes; Moisture barriers; Moisture content; Subgrade (Pavements)
• Uncontrolled Terms: Field performance; Geocomposites; High density polyethylene; Low-density polyethylene
• Geographic Terms: Kaufman County (Texas)
• Subject Areas: Design; Highways; Pavements;

Filing Info

• Accession Number: 01662964
• Record Type: Publication
• Report/Paper Numbers: 18-04256
• Files: TRIS, TRB, ATRI
• Created Date: Mar 19 2018 10:35PM