Abstract
In the current asphalt pavement design method (hereinafter called the TA method), the thickness of each pavement layer is determined based on the specified CBR for the subgrade and the TA value (equivalent thickness) calculated from the total 10-ton conversional number of axes. However, as the highly functional pavement has been introduced for the surface layer, the deterioration conditions of asphalt pavements have changed considerably since the design method and standards were produced, and so we doubt the practical appropriateness of the design based on the TA method. In this study, the error in deterioration lifespan due to the TA method is analyzed. In detail, a mixed Markov deterioration hazard model is estimated by using the FWD inspection data targeted at expressways. By using hazard rate and heterogeneity parameter, the road spans that have unusual deterioration rates are extracted, and the relations between these road spans and the factors that are not considered in the TA method are discussed.
