ABSTRACT
In cold environments such as the one prevailing in the province of Québec (Canada), the two prominent problems associated with frost action are differential frost heave resulting from variable frost action in frost susceptible subgrade soils and frost heave occurring at shallow depths in pavements around cracks. Distortions of the surface profile resulting from frost heave can be divided into short or long wavelength distortions depending on whether or not heaving is associated with crack heaving, or differential frost heaving in the subgrade soil. Identifying the specific cause of profile deterioration during winter through routine analysis of profile and IRI information is currently very difficult to do with existing analysis tools. In order to develop new profile related diagnostic tools, a research project was undertaken on three pavement sections for which winter roughness deterioration causes are well documented. The surface profiles of the experimental sections were measured in summer and winter using an inertial profilometer. For each test section, the IRI difference (ΔIRIuf) between winter and summer profiles, calculated every 100 m, was determined. The measured profiles were also filtered for short wavelengths (1 to 3 m) and long wavelengths (8 to 12 m) in order to determine the IRI difference (ΔIRIf) between winter and summer filtered profiles. The value of the ratio ΔIRIf/ΔIRIuf calculated for each passing wavelength band was used as the main indicator within a decision chart. The proposed method can adequately differentiate the sections affected by deep frost heaving from those affected by shallow crack heaving.
