Structural Design of Pavement for Cold Regions based on Life-Cycle Cost

Resumen

Asphalt pavements in Japan are commonly designed with a 10-year life, regardless of the importance and traffic volume of the route. Toward minimizing the life-cycle cost by extending the service life, the Hokkaido Regional Development Bureau recently revised structural design standards for asphalt pavement to extend the design life to 20 years in cold Hokkaido. The revision focused on low-temperature cracking, frost heaving, and phenomena of cold, snowy climates, as well as on the route's importance and traffic volume. Comparison was made between pavement with a 10-year design life and that with a 20-year design life. Analysis based on multi-layer elasticity theory estimated the number of years before fatigue fracture occurs. Performance curves were obtained by regression analysis of data on longitudinal and transverse profile of the road. Based on these, 50-year life-cycle costs were calculated for 10-year and 20-year design life pavements. A separate case study on national highways in Hokkaido confirmed that extending the design life from 10 years to 20 years could reduce the life-cycle cost more than 10 %.