Estimation of Expected Moisture Contents for Pavements by Environmental and Soil Characteristics

Abstract

Expected moisture contents were evaluated for pavements on the basis of climatic and soil characteristics with the use of the Enhanced Integrated Climatic Model (EICM). Subgrade moisture content varies with environmental and soil conditions and has significant influence on pavement performance. Thus, it is important to establish realistic estimates of expected subgrade moisture contents to account for the effects of this variable on predicted pavement performance during the design stage properly. To predict expected moisture contents, researchers examined regional variations in climatic and soil–water characteristic curves in Texas. Through cluster analysis, seven climatic and nine soil regions were established that captured the variations in climatic and soil characteristics across the state. Typical pavement structures and groundwater table data in different regions were used to reflect regional characteristics and to estimate the initial boundary soil suction profile for a given pavement, which is a critical factor in determining expected moisture variations in the subgrade for given pavement and climatic and soil conditions. The limited verification of the EICM analysis showed realistic predictions of moisture contents when compared with field measurements and confirmed that the results of the regional characterizations are reasonable. Accordingly, researchers evaluated the expected moisture variations across different regions. The results indicate that in most pavements the predicted moisture contents reach an equilibrium stage at some time after construction. From these results, researchers established expected moisture contents that reflect the variation in environmental and soil characteristics across Texas.

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