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Primary Topic: Materials-General
Description: Moisture content plays a significant role in the performance of pavements. Variation in the amount of moisture in the subgrade can change the volume of swelling soil, which may result in detrimental deformation of the pavement structure. An increase in moisture in the subgrade and unbound base can weaken the bearing capacity of these materials, affecting the pavement's response to loads and, ultimately, pavement service life.
The moisture content of unbound materials at LTPP Seasonal Monitoring Program (SMP) sites is computed based on the dielectric constant determined through the use of time-domain reflectometry and soil property data contained in the LTPP Information Management System (IMS) database. A discussion of the use of time-domain reflectometer (TDR) probes and the values derived from them can be found in the computed parameters document, "An Input for Moisture Calculations—Dielectric Constant From Apparent Length" (Publication No. FHWA-RD-99-201), which can also be found on this web site.
FHWA Publication Number: FHWA-RD-00-077
Publication Year: 2000
Document Links: PDF (file size: 0.1 mb)
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