Pavement Structure Evaluation of Alaskan Highways

摘要

A three year study was implemented to review the construction and performance of pavement structures in Alaska. One hundred twenty uniform pavement sections were chosen and characterized by fatigue (alligator) cracking, thermal cracking, roughness of ride and peak springtime deflection levels. Sections were distributed throughout each principle climatic zone within the state. Materials were sampled to a depth of 54 inches and analyzed to determine their relationships to pavement performance. Results indicate correlations between soil fines content and several of the performance factors. Performance relationships were also found involving asphalt concrete thickness, pavement age and accumulated traffic loadings. Climate variables showed little correlation with performance except with major transverse thermal cracks. Deficit thickness-design requirements based on both supporting soils stability (R-value) and frost susceptability were compared with performance for a number of locations. While a trend was observed between existing overlay deficit and performance, the extra materials required by present Alaskan design methods apparently led to overly conservative structures in many cases. Alaska's pavement rating system was also correlated with a more conventional 'PSI' method as developed by New York State.