The design of highway or airport pavements may be governed by subgrade
stress/deformation criteria or frost heave protection requirements. Where the pavement
thickness is controlled by frost heave conditions considerable savings can be realized by
installation of geofoam as insulation. In considering geofoam as a subgrade insulation
element, care should be exercised to minimize development of differential icing. Available
experience suggests that the performance of geofoam insulation depends on tight construction
control to ensure continuity of insulation without gaps. High density geofoams provide higher
initial R-values, deform less under load, and absorb less moisture over time.