Asphalt binder performance grading of North Korea for Superpave asphalt mix-design.

This study is to determine asphalt binder performance grades (PGs) of North Korea (N.K.) so that the asphalt pavement can be designed to resist distresses of rutting and cracking that occurred due to seasonal temperature changes. The first step of determining the PG is to establish high and low temperatures for a location because the asphalt binder is a temperature sensitive viscoelastic material. The temperature zoning for developing the PG map were performed by obtaining last 26 year temperature data of 27 cities in N.K. from world meteorological organization. A trend and statistical reliability of the temperature data were analyzed to secure asphalt binder performance. Three air-pavement temperature prediction models of Superpave, South Korea, and Japan were utilized to predict the pavement temperatures. Finally, the reliability levels of 98% and 50% were used to determine the local PGs. Since the Superpave equation includes the dependent variable of latitude that can more reflect geographic locations of North areas rather than the other models, this study finally adopted the SHRP Superpave model to determine the binder PGs. Based on the Superpave models with the reliability analyses, PG maps were drawn. It was found out that the most common grades used for low volume roads are PG 58-22 and 58-28, covering 79% and 93% of the N.K. area. [ABSTRACT FROM AUTHOR]