Long Term Pavement Performance Computed Parameter: Frost Penetration

As the pavement design process moves toward mechanistic-empirical techniques, knowledge of seasonal changes in pavement structural characteristics becomes critical. Specifically, frost penetration information is necessary for determining the effect of freeze and thaw on pavement structural responses. This report describes a methodology for determining frost penetration in unbound pavement layers and subgrade soil using temperature, electrical resistivity, and moisture data collected for instrumented Long Term Pavement Performance (LTPP) Seasonal Monitoring Program (SMP) sites. The report also contains a summary of LTPP frost depth estimates and a detailed description of the LTPP computed parameter tables containing frost penetration information for 41 LTPP SMP sites. The frost penetration analysis methodology and the accompanying E-FROST program used in-situ soil temperature as a primary source of data to predict frost depth in unbound pavement layers. In addition to temperature data, electrical resistivity and moisture data were used as supplemental data sources for the analysis when temperatures were close to the freezing isotherm. The Enhanced Integrated Climatic Model (EICM) was used to fill intermediate gaps in the measured soil temperature data.