Measurements of Seasonal Changes and Spatial Variation in Pavement Subgrade Support Properties: A Link to Pavement Performance (TR-516)

Project Details
STATUS

Completed

PROJECT NUMBER

04-172, TR-516

START DATE

05/01/04

END DATE

05/31/08

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, CEER, CTRE
SPONSORS

Iowa Department of Transportation
Iowa Highway Research Board

Researchers
Principal Investigator
David White
Co-Principal Investigator
Radhey Sharma
Co-Principal Investigator
Vern Schaefer
Co-Principal Investigator
Charles Jahren
Student Researcher(s)
Matthew Cushman
Thang Phan

About the research

Seasonal variations in ground temperature and moisture content influence the load carrying capacity of pavement subgrade layers. To improve pavement performance, pavement design guidelines require knowledge of environmental factors and subgrade stiffness relationships.

As part of this study, in-ground instrumentation was installed in the pavement foundation layers of a newly constructed section along US Highway 20 near Fort Dodge, Iowa, to monitor the seasonal variations in temperature, frost depth, groundwater levels, and moisture regime. Dynamic cone penetrometer (DCP), nuclear gauge, and Clegg hammer tests were performed at 64 test points in a 6 ft x 6 ft grid pattern to characterize the subgrade stiffness properties (i.e., resilient modulus) prior to paving. The purpose of this project is to present the field instrumentation results and the observed changes in soil properties due to seasonal environmental effects.

 

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