Backcalculation of unbound granular layer moduli.

Details

• Creators:
  Baladi, Gilbert Y. ; Thottempudi, Ashvini ; Dawson, Tyler
• Corporate Creators:
  Michigan State University. Dept. of Civil and Environmental Engineering
• Corporate Contributors:
  Michigan. Dept. of Transportation. Construction and Technology Division
• Subject/TRT Terms:
  • Subbase (Pavements)
  • Subbase materials
  • Subgrade materials
  • Foundation soils
  • Granular bases
  • Base course (Pavements)
  • Backcalculation
  • Nondestructive tests
  • Freeze thaw durability
  • Modulus
• Resource Type:
  Tech Report
• Geographical Coverage:
  Michigan
• Corporate Publisher:
  Michigan. Dept. of Transportation
• Abstract:
  The state of Michigan is geographically located within the wet-freeze zone identified by the ; American Association of States and Highway Transportation Officials (AASHTO). The frost ; depth in the State ranges from 2.5 feet near the Ohio and Indiana borders to about 5.0 feet in ; parts of the Upper Peninsula. To minimize the impact of freeze-thaw cycles on pavement ; performance, granular subbase (typically sand) and base (typically gravel) layers are ; conventionally used to provide protection to the roadbed soils from the detrimental effects of ; freezing and to minimize the stresses delivered to the roadbed soils. In general, the strengths of ; the granular layers are lower than that of the asphalt or concrete surface layer and, in most cases, ; higher than the strength of the roadbed soils. The most common and available aggregate types ; used by the Michigan Department of Transportation (MDOT) in pavement construction include ; natural gravel, limestone/dolomite, slag, and crushed concrete. In this study, the value of the ; resilient modulus of commonly used granular materials were backcalculated using two- and ; three-layer systems and Nondestructive Deflection Test (NDT) data obtained by MDOT. The ; backcalculated resilient modulus values of the unbound granular layers were subjected to various ; to determine the most appropriate values to be used in the pavement design process. This final ; report provides details of the analyses and the resulting outcomes.
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• Format:
  PDF
• Funding:
  RC-1548
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/23290/dot_23290_DS1.pdf
• File Type:
  [PDF - 2.85 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:048fd7b6d0a078e309096f21dade8b6fcf1e714947ebafe007911bf8eed4d80f76f178d018a78ba0a4462c78919e5304cee7fb57e4a2b13fe922657d31b74d2a