Effects of Seasonal Changes on Ride Quality at MnROAD

Summary

This project studied frost heave as it relates to different pavement design parameters and ride quality deterioration. Elevations of frost pins embedded in MnROAD test sections were measured over four years. Pin elevation changes were analyzed to show the amount of frost heave and degree of frost heave uniformity within a cell. Various plots were made to show the elevation change and interquartile range of the pins over time. Statistical approaches such as visual analyses, Student-t hypothesis testing, and ANOVA analysis were used in this study to evaluate the effect of pavement design features on frost heave and roughness.

Subgrade and base type, pavement thickness, and drainage capabilities are the major design factors that affect frost heave. The effects of frost heave on ride quality deterioration for flexible and rigid pavements could not be confirmed or statistically rejected in this study. No seasonal adjustment factor for IRI measurement is recommended for use in a pavement management system because no firm conclusions could be made from the data concerning a seasonal effect on IRI measurements.